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5 Animals That Can Take the Extreme Heat—and Cold

It’s the ultimate deep freeze: Wood frogs in Alaska have set a record for cold endurance, staying as frozen as your microwave dinner for nearly seven months, a new study says.

Scientists at the University of Alaska Fairbanks discovered that the amphibians survived all those months being chilled to an average temperature of 6°F (-14.6°C), including temperatures as low as 0°F (-18°C).

Wood Frog
A wood frog (Rana sylvatica) from Anchorage, Alaska. Photograph by Carl Battreall/Nature Picture Library/Corbis

“No other vertebrate has ever shown this duration of freeze tolerance,” said biologist Don Larson, lead author on a study published recently in the Journal of Experimental Biology.

It’s a remarkable feat. Studies of wood frogs in laboratories had led scientists to believe they couldn’t survive such temperatures for more than a couple of months at most.

Larson already knew from laboratory frogs that the animals pack their cells with glucose, a sugar, to stabilize their cells and prevent water loss. But after sampling the tissue of 18 wild wood frogs overwintering in shallow depressions near their spring breeding ponds, he realized that they were even better at this process, known as cryoprotection.

When compared with frozen lab frogs, the wild frogs had glucose concentrations that were 13 times as high in muscle tissue, 10 times as high in heart tissue, and 3.3 times as high in liver tissue.

Larson believes the frogs accomplish this glucose spike through a freeze-thaw process not seen in laboratories. In the wild, temperatures shift, so hibernating frogs will begin to thaw out, then freeze again as night falls—which ups their stores of glucose. (See “Antifreeze-Like Blood Lets Frogs Freeze and Thaw With Winter’s Whims.”)

In fact, the frogs are so efficient at regulating their freeze-thaw cycles, Larson said, that “they’re actually spending more time frozen than a lot of food is capable of staying safe to eat.”

Among vertebrates, the wood frog may be the most cold tolerant. But in the broader animal kingdom, others give the frog a run for its money when it comes to making it through a cold winter’s night—or a hot summer’s day.

Red Flat Bark Beetle (Cucujus clavipes puniceus)

This North American beetle has a broad range that extends from North Carolina to the Arctic Circle.

Accordingly, the beetle has developed a serious ability to avoid freezing. Individuals can drop to temperatures as low as -72°F (-58°C), and their larvae can endure even more remarkable lows without freezing—around -148°F (-100°C).

Red Flat Bark Beetle.
A red flat bark beetle. Photograph by Bill Beatty/Visuals Unlimited/Corbis

To achieve this, the bark beetle accumulates antifreeze proteins and glycerol—a sugary alcohol that’s the basis for many antifreeze products—in its tissues while reducing its metabolism and entering a state of dehydration in order to avoid a frozen, rock-solid state.

Dehydration increases concentrations of the antifreeze proteins and glycerol, while simultaneously decreasing the amount of water that’s available to freeze.

Combined, these factors allow the beetle to maintain an on-and-off active lifestyle in some of the harshest conditions on the planet. (See: “Animal ‘Zombies’: Nature’s ‘Walking Dead’ in Pictures.”)

Pompeii Worm (Alvinella pompejana)

Named for the hydrothermal vents near where it lives, this underwater critter thrives in temperatures that are almost hot enough to boil water.

The Pompeii worm is the world’s most heat-tolerant multicelled creature, able to withstand temperatures above 176°F (80°C).

Scientists believe the worm is able to tolerate such scorching temperatures because of a mutually beneficial relationship with a mysterious fuzzy bacterium. The bacterium appears to insulate the worm, protecting it from the heavy metals churned out by the seafloor’s vents.

Sahara Desert Ant (Cataglyphis bicolor)

The Pompeii worm may rule the ocean’s depths, but the Sahara desert ant is one tough land dweller. The insect forages even when its body temperature is above 122°F (50°C), making it one of the most heat-tolerant species to walk the Earth.

Ant (Cataglyphis bicolor).
Sahara desert ants with an unidentified insect. Photograph by blickwinkel/Alamy

Its long legs keep its body off the hot desert sand, where temperatures can be ten degrees warmer.

Most intriguing, though, is its hunting strategy. The Sahara desert ant is the only ant that continues to look for food once temperatures rise above 113°F (45°C). Under a broiling sun, they scavenge the corpses of other ants and insects that couldn’t handle the heat.

Water Bear or Tardigrade (Hypsibius dujardini)

As tough (and cannibalistic) as the Sahara desert ant may sound, nothing beats the water bear, also known as a tardigrade or moss piglet. It’s the king of extreme temperatures, capable of surviving lows near absolute zero (-459°F; -273°C) and highs of more than 302°F (150°C).

Water bear. This tiny invertebrate lives in aquatic and semi-aquatic habitats such as lichen and damp moss.
Water bears live in aquatic and semiaquatic habitats such as lichen and damp moss. Photograph by Steve Gschmeissner/Science Photo Library/Corbis

Found in hot springs, nestled under solid ice, and at the top of the Himalaya, these tiny invertebrates can even survive outer space.

In 2007 Swedish researcher K. Ingemar Jönsson rocketed a few tardigrades into space using the FOTON-M3 spacecraft. Even after being exposed to the vacuum and cosmic rays of space, they lived.

Now that’s tolerance of astronomical proportions.

Follow Gloria Dickie on Twitter.



  1. Jeremy
    January 16, 12:22 am

    Why does this say the Pompeii Worm is the most heat-tolerant multicelled creature? For one thing, if it was the most heat-tolerant known, it should say most heat-tolerant known. Not just the most heat-tolerant. Because there could be a more heat-tolerant one unknown. For another thing, it contradicts saying it’s the most heat-tolerant known when it says Tardigrade is the king of extreme temperatures.

  2. Neil r thorley
    December 27, 2016, 2:52 pm

    Truly amazing creatures,did they come from another planet???

  3. Privacy
    Beyond the Solar System
    November 14, 2016, 11:25 pm

    Tardigrade are adorable. Still love Axolotls more though.

    August 19, 2016, 7:42 am


  5. Dank Meme
    April 29, 2016, 11:47 am

    I don’t like that bug it scary!!!

  6. Len Aubertin
    Welland Ontario
    February 9, 2016, 4:43 pm

    I would like to mix the Tardigrades DNA with mine and see what happens.

  7. Patrick
    December 9, 2014, 8:59 am

    One day, I will extract the incredible genes from the tardigrades and put them in crops to enhance my country’s crop production by minimizing abiotic stresses like high temperature.

  8. Darwin
    The Universe
    October 15, 2014, 5:09 am

    Evolution is the answer and there is no faintest trace of a God scientifically

  9. Jacob Sherk
    August 11, 2014, 11:26 pm

    Very fascinating organisms indeed, Very fascinating post too
    what I want to know about the Water Bear though is its size,
    its just so cute don’t you all agree?

  10. Nathaniel
    August 6, 2014, 6:04 am

    This is great indeed.

  11. Ken
    August 5, 2014, 3:56 pm

    How long does it take National Geographic to correct an error in their articles even after it has been pointed out to them?

  12. Rafael Tonolete
    August 5, 2014, 3:45 pm

    If we can discover how we can have the capability of the Tardigrade to endure extremities of Temperature and environment, we could be super humans or extend human species to forever.

  13. smart egbowon
    August 4, 2014, 10:17 am

    This shows that we humans were meant for all eternity on earth because we can’t discover all of nature even in a millenium.Incredible creatures!Nature is really the art of God.

  14. Pepe Durá
    August 4, 2014, 7:04 am

    And what about the Emperor penguin?

  15. Jon
    August 3, 2014, 5:50 pm

    If the water bear can survive like that, the chance we will find them on other worlds is, in my opinion, high.

  16. Shane C
    Red DeerAB
    August 2, 2014, 10:05 am

    The diversities and complex life forms in nature on this planet are mind boggling. Even though the ecosystem is fragile within it are some not so fragile things.

  17. Rogier
    New Zealand
    August 2, 2014, 7:18 am

    The tree weta has a special protein in their blood that prevents water from freezing, allowing them to go into a deep freeze and still have their blood flowing when they wake back up.
    They’re not just resistant to freezing, their brains and hearts actually completely die when frozen, then somehow recover good as new when thawed out.
    It dies, and then it lives again. It is undead.
    You can also keep them under water for four days. Incredibly, it keeps living, as they also do when you drop them in near boiling water.

  18. Rogier
    New Zealand
    August 2, 2014, 6:44 am

    The WETA can withstand also freezing and cooking heat.

  19. Benjamin Zumberi
    Bosnia and Herzegowina
    August 2, 2014, 6:36 am

    These animals are so amazing. We can learn a lot from them.

  20. William Housworth
    United States
    August 1, 2014, 7:52 pm

    That is so cool! I’m a big fan of National Geographic!

  21. Paul Scutts
    August 1, 2014, 1:06 pm

    What is really interesting about these extremophiles is what we can learn from their natural abilities. For example, the ability of the wood frog to freeze, thaw, re-freeze and re-thaw could one day be adapted to put human beings into a state of recoverable suspended animation. Science fiction becoming science fact.

  22. subrata
    August 1, 2014, 8:38 am

    It’s really amazing…

  23. Edun
    August 1, 2014, 3:38 am

    Your effort to study nature and discover these beautify creatures is very commendable

  24. Ahmed Abdelmajeed
    United Stats
    July 31, 2014, 11:42 pm

    When I read about these species I believe more there is a Creator

  25. Tanmay Sharma
    July 31, 2014, 3:06 am

    Gosh!! what in the world are these species made of? They have supernatural power.