The wood frog (Rana sylvatica) survives being frozen solid for weeks each winter — its heart stops, its blood stops flowing, and up to 65% of its body water turns to ice — then it thaws and hops away in spring.
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The wood frog freezes completely solid each winter — heart stopped, blood frozen — then thaws in spring and hops away like nothing happened. Up to 65% of its body water turns to ice, and it survives using glucose as a natural antifreeze. Scientists are studying this remarkable mechanism to improve human organ preservation for transplants. Follow for a new fact every day.
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This small frog literally freezes solid every winter and comes back to life. The wood frog, found across North America, survives temperatures as low as minus 16 degrees Celsius by allowing up to 65% of its body water to turn to ice. Its heart stops completely. Its blood stops flowing. By every clinical measure, it is dead. The secret is glucose. The frog floods its cells with sugar, acting like antifreeze that keeps ice crystals from shredding tissues from the inside. It can stay in this frozen state for weeks beneath leaf litter in the snow. Then spring arrives, the ice melts, and the heart restarts on its own. Scientists at Miami University in Ohio have studied this mechanism as a model for improving human organ preservation for transplant. Follow for a fact every day.
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