As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

Discovering how the moon shapes life on Earth.

An epic journey into the unknown, a realm that feels almost like science fiction.

As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

A bald eagle needs Hope's help; a small but lethal patient keep the entire staff on their toes.

A team of astronomers determine the ultimate fate of Earth, several billion years from now.

St. John's Newfoundland and the Avalon peninsula to the unique islands.

A bald eagle needs Hope's help; a small but lethal patient keep the entire staff on their toes.

A team of astronomers determine the ultimate fate of Earth, several billion years from now.

St. John's Newfoundland and the Avalon peninsula to the unique islands.

A bald eagle needs Hope's help; a small but lethal patient keep the entire staff on their toes.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Professor Cox explores the cycles of time that define the lives of humans.

Along the coastline, Zac and Darin take a deep dive into the coral reef restoration techniques supporting a vast underwater ecosystem.

Levison reunites with his old friend Binod Parya who once saved his life.

Levison resumes his journey in Nepal, visiting a crash site 150 meters down a steep cliff.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Coral Reefs are vibrant undersea cities where life has found ways to survive.

A race to find the planet's 60 deadliest creatures.

Steve and the crew travel 4,000 miles to the Loango National Park in Gabon; Steve heads out into Loango's maze of rivers on a mission to try and find an animal that is critically endangered but packs a mighty punch, the western lowland gorilla.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

A race to find the planet's 60 deadliest creatures.

Steve and the crew travel 4,000 miles to the Loango National Park in Gabon; Steve heads out into Loango's maze of rivers on a mission to try and find an animal that is critically endangered but packs a mighty punch, the western lowland gorilla.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Professor Cox explores the cycles of time that define the lives of humans.

Coral Reefs are vibrant undersea cities where life has found ways to survive.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

A hunt for a misunderstood coyote; the ravens have worn out their welcome and need a new home.

Missions are heading to Jupiter to discover how planets form and to find out if there is life on the planets four largest moons.

From St. John's heading north, the coastline is a maze of bays and inlets.

A hunt for a misunderstood coyote; the ravens have worn out their welcome and need a new home.

Missions are heading to Jupiter to discover how planets form and to find out if there is life on the planets four largest moons.

From St. John's heading north, the coastline is a maze of bays and inlets.

A hunt for a misunderstood coyote; the ravens have worn out their welcome and need a new home.

With seasons changing in the Arctic, Alaskans hunt before the spring breakup fully arrives.

The same 92 elements that exist on Earth can be found throughout the cosmos.

A race to find the planet's 60 deadliest creatures.

Steve and the crew travel 4,000 miles to the Loango National Park in Gabon; Steve heads out into Loango's maze of rivers on a mission to try and find an animal that is critically endangered but packs a mighty punch, the western lowland gorilla.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

With seasons changing in the Arctic, Alaskans hunt before the spring breakup fully arrives.

The big blue is the world's greatest wilderness, far from shore and many kilometers deep.

Gordon Buchanan returns to Russia to help Dr. Victor Lukarevsky prepare rehabilitated lynx for release back in the wild.

Remote islands offer sanctuary; pygmy three-toed sloth resides on a Caribbean island; nesting albatross thrive in isolation.

In southeast Alaska, there's an ice-bound Eden that harbors possibly the richest temperate rainforests of all.

Gordon Buchanan returns to Russia to help Dr. Victor Lukarevsky prepare rehabilitated lynx for release back in the wild.

Remote islands offer sanctuary; pygmy three-toed sloth resides on a Caribbean island; nesting albatross thrive in isolation.

In southeast Alaska, there's an ice-bound Eden that harbors possibly the richest temperate rainforests of all.

With seasons changing in the Arctic, Alaskans hunt before the spring breakup fully arrives.

The same 92 elements that exist on Earth can be found throughout the cosmos.

The big blue is the world's greatest wilderness, far from shore and many kilometers deep.

With seasons changing in the Arctic, Alaskans hunt before the spring breakup fully arrives.

Allison brings her work home; some orphans try to make a break for it while Allison and Hope are away.

The diamond's rise from gemstone to a cutting-edge material that is set to revolutionize electronics.

A journey on Scotland's River Spey, traveling from its source in the Highlands, winding by boat through the mountains to where the river meets the North Sea.

Allison brings her work home; some orphans try to make a break for it while Allison and Hope are away.

The diamond's rise from gemstone to a cutting-edge material that is set to revolutionize electronics.

A journey on Scotland's River Spey, traveling from its source in the Highlands, winding by boat through the mountains to where the river meets the North Sea.

Allison brings her work home; some orphans try to make a break for it while Allison and Hope are away.

As the snow melts and the ice on the waterways breaks up, the Arctic becomes a land of opportunity; the Hailstones hunt; Sue Aikens reopens her greenhouse; Glenn Villeneuve returns home.

A look at how gravity affects the world, and even the solar system.

Gordon Buchanan returns to Russia to help Dr. Victor Lukarevsky prepare rehabilitated lynx for release back in the wild.

Remote islands offer sanctuary; pygmy three-toed sloth resides on a Caribbean island; nesting albatross thrive in isolation.

In southeast Alaska, there's an ice-bound Eden that harbors possibly the richest temperate rainforests of all.

As the snow melts and the ice on the waterways breaks up, the Arctic becomes a land of opportunity; the Hailstones hunt; Sue Aikens reopens her greenhouse; Glenn Villeneuve returns home.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

Alaskans must capitalize on the resources of the Arctic Summer.

All crews race toward the end of the season on March 31, desperate to make quota before they're forced off the ice; emotions run high as the Kristjanson crew surveys the damage and recovers what's left of Trevor's narrow gauge bomber.

Scientists are using technology to research weather on other planets.

Alaskans must capitalize on the resources of the Arctic Summer.

All crews race toward the end of the season on March 31, desperate to make quota before they're forced off the ice; emotions run high as the Kristjanson crew surveys the damage and recovers what's left of Trevor's narrow gauge bomber.

Scientists are using technology to research weather on other planets.

As the snow melts and the ice on the waterways breaks up, the Arctic becomes a land of opportunity; the Hailstones hunt; Sue Aikens reopens her greenhouse; Glenn Villeneuve returns home.

A look at how gravity affects the world, and even the solar system.

All crews race toward the end of the season on March 31, desperate to make quota before they're forced off the ice; emotions run high as the Kristjanson crew surveys the damage and recovers what's left of Trevor's narrow gauge bomber.

As the snow melts and the ice on the waterways breaks up, the Arctic becomes a land of opportunity; the Hailstones hunt; Sue Aikens reopens her greenhouse; Glenn Villeneuve returns home.

The open house is bigger than ever, which brings about more challenges.

Scientists explore whether Earth's estranged twin Venus could be a vision of our planet's future.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

The open house is bigger than ever, which brings about more challenges.

Scientists explore whether Earth's estranged twin Venus could be a vision of our planet's future.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

The open house is bigger than ever, which brings about more challenges.

Alaskans need to adapt and shift their plans due to unpredictable winter weather.

Brian Cox explores the fundamental properties of light; the secrets of the cosmos.

Alaskans must capitalize on the resources of the Arctic Summer.

All crews race toward the end of the season on March 31, desperate to make quota before they're forced off the ice; emotions run high as the Kristjanson crew surveys the damage and recovers what's left of Trevor's narrow gauge bomber.

Scientists are using technology to research weather on other planets.

Alaskans need to adapt and shift their plans due to unpredictable winter weather.

From forests to undersea prairies, it is the green of the sea that brings life to oceans.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think.

Hunting for evidence of life beyond Earth; a look through sensitive telescopes; the detective work of scientists in the search for possible alien populations.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think.

Hunting for evidence of life beyond Earth; a look through sensitive telescopes; the detective work of scientists in the search for possible alien populations.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

Alaskans need to adapt and shift their plans due to unpredictable winter weather.

Brian Cox explores the fundamental properties of light; the secrets of the cosmos.

From forests to undersea prairies, it is the green of the sea that brings life to oceans.

Alaskans need to adapt and shift their plans due to unpredictable winter weather.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Hubble's Canvas reveals the masterpieces that abound in the universe.

Hubble's Canvas reveals the masterpieces that abound in the universe.

Griff Rhys Jones begins his exploration of Ontario and ponders why Canadians are so nice.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Hubble's Canvas reveals the masterpieces that abound in the universe.

Hubble's Canvas reveals the masterpieces that abound in the universe.

Griff Rhys Jones begins his exploration of Ontario and ponders why Canadians are so nice.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think.

Gordon Buchanan returns to Russia to help Dr. Victor Lukarevsky prepare rehabilitated lynx for release back in the wild.

An epic journey into the unknown, a realm that feels almost like science fiction.

Coral Reefs are vibrant undersea cities where life has found ways to survive.

The big blue is the world's greatest wilderness, far from shore and many kilometers deep.

From forests to undersea prairies, it is the green of the sea that brings life to oceans.

Alaskans must capitalize on the resources of the Arctic Summer.

It is high summer in the polar regions, and the sun never sets; many species take advantage of the easier conditions, but summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson.

Professor Brian Cox explores how the universe began and how it will end.

The team battle through the jungle into the heart of Indonesian Borneo, where a remote mountain range guards caves, holding secrets that could rewrite history.

It is high summer in the polar regions, and the sun never sets; many species take advantage of the easier conditions, but summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson.

Professor Brian Cox explores how the universe began and how it will end.

The team battle through the jungle into the heart of Indonesian Borneo, where a remote mountain range guards caves, holding secrets that could rewrite history.

It is high summer in the polar regions, and the sun never sets; many species take advantage of the easier conditions, but summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think.

Hunting for evidence of life beyond Earth; a look through sensitive telescopes; the detective work of scientists in the search for possible alien populations.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

After being dropped into the woods with no supplies, six Indigenous strangers learn to patch birchbark canoes.

Gabriella and the others experience a wet, cold night; Elder Charlie demonstrates the art of starting fire; Michela's fears grow.

British comedian and travel enthusiast Griff Rhys Jones explores the frozen wilds of Canada's north, in the province of Manitoba.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

After being dropped into the woods with no supplies, six Indigenous strangers learn to patch birchbark canoes.

Gabriella and the others experience a wet, cold night; Elder Charlie demonstrates the art of starting fire; Michela's fears grow.

British comedian and travel enthusiast Griff Rhys Jones explores the frozen wilds of Canada's north, in the province of Manitoba.

Alaskans must capitalize on the resources of the Arctic Summer.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think.

Hunting for evidence of life beyond Earth; a look through sensitive telescopes; the detective work of scientists in the search for possible alien populations.

Levison reunites with his old friend Binod Parya who once saved his life.

Levison resumes his journey in Nepal, visiting a crash site 150 meters down a steep cliff.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

A race to find the planet's 60 deadliest creatures.

Steve and the crew travel 4,000 miles to the Loango National Park in Gabon; Steve heads out into Loango's maze of rivers on a mission to try and find an animal that is critically endangered but packs a mighty punch, the western lowland gorilla.

Gordon Buchanan returns to Russia to help Dr. Victor Lukarevsky prepare rehabilitated lynx for release back in the wild.

From forests to undersea prairies, it is the green of the sea that brings life to oceans.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

Remote islands offer sanctuary; pygmy three-toed sloth resides on a Caribbean island; nesting albatross thrive in isolation.

From forests to undersea prairies, it is the green of the sea that brings life to oceans.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

Remote islands offer sanctuary; pygmy three-toed sloth resides on a Caribbean island; nesting albatross thrive in isolation.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

With seasons changing in the Arctic, Alaskans hunt before the spring breakup fully arrives.

As the snow melts and the ice on the waterways breaks up, the Arctic becomes a land of opportunity; the Hailstones hunt; Sue Aikens reopens her greenhouse; Glenn Villeneuve returns home.

Alaskans need to adapt and shift their plans due to unpredictable winter weather.

Never seen before footage of Hope's greatest stories.

Some of the world's greatest scientists devise scenarios for destroying Earth.

The journey down the attraction-packed Niagara River is filled with adventure and beauty; navigating the fascinating history and engineering of this border river between Canada and the United States, arriving at the world-famous Niagara Falls.

Never seen before footage of Hope's greatest stories.

Some of the world's greatest scientists devise scenarios for destroying Earth.

The journey down the attraction-packed Niagara River is filled with adventure and beauty; navigating the fascinating history and engineering of this border river between Canada and the United States, arriving at the world-famous Niagara Falls.

Never seen before footage of Hope's greatest stories.

As the rivers melt, Alaskans try to stay ahead of the changing landscape.

Two brilliant physicists, Albert Einstein and Stephen Hawking have each defined humanity's understanding of the universe but their beliefs on how it works do not always align.

Asia has the longest coastline of any continent, rich coral reefs, and never-seen-before animal behavior; exploring Asia's diverse waters.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

The team battle through the jungle into the heart of Indonesian Borneo, where a remote mountain range guards caves, holding secrets that could rewrite history.

As the rivers melt, Alaskans try to stay ahead of the changing landscape.

Coasts are the most changeable habitats of the ocean world.

Zac and Darin test their cooking skills in Melbourne, Australia, before heading to the Torres Strait Islands to understand the impact of rising sea levels.

Accompanied by his old friend and guide Binod, Levison tracks the mountains from eastern Nepal into the country of Bhutan.

Levison and Alberto begin their journey on the northern shores of Mexico's Yucatan Peninsula.

Zac and Darin test their cooking skills in Melbourne, Australia, before heading to the Torres Strait Islands to understand the impact of rising sea levels.

Accompanied by his old friend and guide Binod, Levison tracks the mountains from eastern Nepal into the country of Bhutan.

Levison and Alberto begin their journey on the northern shores of Mexico's Yucatan Peninsula.

As the rivers melt, Alaskans try to stay ahead of the changing landscape.

Two brilliant physicists, Albert Einstein and Stephen Hawking have each defined humanity's understanding of the universe but their beliefs on how it works do not always align.

Coasts are the most changeable habitats of the ocean world.

As the rivers melt, Alaskans try to stay ahead of the changing landscape.

A huge storm sweeps an unusual patient into Hope for Wildlife, and Hope tries to return him to his home.

Strange aquatic mammals populating a river in Columbia; a ship marooned in a sea of sand along Namibia's notorious Skeleton Coast; a Boeing 727 jetliner hidden in a pine forest; an unusual pattern is discovered in the Nevada desert.

A breathtaking journey down the German section of the beautiful Moselle river, famous for vineyards on its dramatically steep banks and remarkable meandering loops.

A huge storm sweeps an unusual patient into Hope for Wildlife, and Hope tries to return him to his home.

Strange aquatic mammals populating a river in Columbia; a ship marooned in a sea of sand along Namibia's notorious Skeleton Coast; a Boeing 727 jetliner hidden in a pine forest; an unusual pattern is discovered in the Nevada desert.

A breathtaking journey down the German section of the beautiful Moselle river, famous for vineyards on its dramatically steep banks and remarkable meandering loops.

A huge storm sweeps an unusual patient into Hope for Wildlife, and Hope tries to return him to his home.

Alaskans race to gather resources while battling challenges from unpredictable weather.

Two brilliant physicists, Albert Einstein and Stephen Hawking have each defined humanity's understanding of the universe but their beliefs on how it works do not always align.

Zac and Darin test their cooking skills in Melbourne, Australia, before heading to the Torres Strait Islands to understand the impact of rising sea levels.

Accompanied by his old friend and guide Binod, Levison tracks the mountains from eastern Nepal into the country of Bhutan.

Levison and Alberto begin their journey on the northern shores of Mexico's Yucatan Peninsula.

Alaskans race to gather resources while battling challenges from unpredictable weather.

Pioneers strive to protect the ocean from the effects of human activity.

A race to find the planet's 60 deadliest creatures.

Bonus footage from throughout the series, including a race with a cheetah, a cute but deadly bird, and a king cobra rescue; rare occasions when things do not go to plan.

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

A race to find the planet's 60 deadliest creatures.

Bonus footage from throughout the series, including a race with a cheetah, a cute but deadly bird, and a king cobra rescue; rare occasions when things do not go to plan.

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

Alaskans race to gather resources while battling challenges from unpredictable weather.

Two brilliant physicists, Albert Einstein and Stephen Hawking have each defined humanity's understanding of the universe but their beliefs on how it works do not always align.

Pioneers strive to protect the ocean from the effects of human activity.

Alaskans race to gather resources while battling challenges from unpredictable weather.

Hope cares for the first two beavers to arrive at the rehab centre and learns the fate of her most famous patient.

An enormous fiery vortex in Redding, California, the island nation of Malta loses a natural treasure, a mysterious radioactive hotspot is discovered near Chernobyl, and an unknown force lays waste to a mountain forest in Italian Alps.

New York's Hudson River stretches 315 miles through natural landscapes, from the Adirondack Mountains to the George Washington Bridge and Statue of Liberty.

Hope cares for the first two beavers to arrive at the rehab centre and learns the fate of her most famous patient.

An enormous fiery vortex in Redding, California, the island nation of Malta loses a natural treasure, a mysterious radioactive hotspot is discovered near Chernobyl, and an unknown force lays waste to a mountain forest in Italian Alps.

New York's Hudson River stretches 315 miles through natural landscapes, from the Adirondack Mountains to the George Washington Bridge and Statue of Liberty.

Hope cares for the first two beavers to arrive at the rehab centre and learns the fate of her most famous patient.

As the summer begins to fade, Alaskans must take advantage of the long days to prepare for the long freeze that lies ahead.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

A race to find the planet's 60 deadliest creatures.

Bonus footage from throughout the series, including a race with a cheetah, a cute but deadly bird, and a king cobra rescue; rare occasions when things do not go to plan.

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

As the summer begins to fade, Alaskans must take advantage of the long days to prepare for the long freeze that lies ahead.

With food in abundance it's a time of plenty in the Serengeti; a series of unexpected events turns families against each other and stretches relationships to breaking point.

Behind nature's winter wonderland are some of the toughest places to survive. Hidden cameras in a new generation of Spy Creatures reveal the fascinating behaviors of animals from penguins to parrots, polar bears to otters, wallabies, and wombats.

The secretive lives of mountain animals; snow leopards come together to help a mother and cub, trapped between rival males.

Extreme locales include Mount Everest's Khumbu Icefall, the Grand Canyon, and the slopes of Mount Kilimanjaro.

Behind nature's winter wonderland are some of the toughest places to survive. Hidden cameras in a new generation of Spy Creatures reveal the fascinating behaviors of animals from penguins to parrots, polar bears to otters, wallabies, and wombats.

The secretive lives of mountain animals; snow leopards come together to help a mother and cub, trapped between rival males.

Extreme locales include Mount Everest's Khumbu Icefall, the Grand Canyon, and the slopes of Mount Kilimanjaro.

As the summer begins to fade, Alaskans must take advantage of the long days to prepare for the long freeze that lies ahead.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

With food in abundance it's a time of plenty in the Serengeti; a series of unexpected events turns families against each other and stretches relationships to breaking point.

As the summer begins to fade, Alaskans must take advantage of the long days to prepare for the long freeze that lies ahead.

Hope and Dr. Barry have their hands full wrangling five baby black bears.

A long-forgotten network of Native American earthworks, a baffling battlefield mystery in Belgium, a mysterious blood red lake on a remote Greek island, and an eerie pink glow emulating form the middle of the Pacific Ocean.

Bill Nighy narrates a trip along the River Po, traveling across northern Italy from the snow-capped Alps to the delta where it meets the Adriatic Sea.

Hope and Dr. Barry have their hands full wrangling five baby black bears.

A long-forgotten network of Native American earthworks, a baffling battlefield mystery in Belgium, a mysterious blood red lake on a remote Greek island, and an eerie pink glow emulating form the middle of the Pacific Ocean.

Bill Nighy narrates a trip along the River Po, traveling across northern Italy from the snow-capped Alps to the delta where it meets the Adriatic Sea.

Hope and Dr. Barry have their hands full wrangling five baby black bears.

Alaskans must ensure they are prepared to withstand the extreme cold that lies ahead.

Helen Czerski reveals how life began when hot met cold, and how every single living creature on Earth depends on temperature for its survival; she witnesses the remarkable surgery that uses temperature to push the human body to the brink of life.

Behind nature's winter wonderland are some of the toughest places to survive. Hidden cameras in a new generation of Spy Creatures reveal the fascinating behaviors of animals from penguins to parrots, polar bears to otters, wallabies, and wombats.

The secretive lives of mountain animals; snow leopards come together to help a mother and cub, trapped between rival males.

Extreme locales include Mount Everest's Khumbu Icefall, the Grand Canyon, and the slopes of Mount Kilimanjaro.

Alaskans must ensure they are prepared to withstand the extreme cold that lies ahead.