The blood from woolly mammoths is helping scientists develop new blood products for medical procedures such as heart and brain surgery.
Many such operations require artificial hypothermia to be induced by drastically reducing the patient's body temperature.
While woolly mammoth ancestors initially evolved in warm climates, where African and Asian elephants live now, they migrated to the cold regions of Eurasia between 1.2 million and two million years ago, during the Pleistocene ice age.
Here, they adapted to the cold by growing thick, woolly fur and developing smaller ears, to conserve heat, and possibly by changing their DNA.
Earlier, Chien Ho of the American Chemical Society and colleagues had discovered that the mammoth's hemoglobin - the blood protein that carries oxygen from the lungs to the rest of the body - has mutations in its DNA that make it different from that of its cousin, the Asian elephant.
Without a woolly mammoth blood sample to work with, they made the hemoglobin protein in the laboratory by using fragmented DNA sequences from three mammoths that died in Siberia between 25,000 and 43,000 years ago.
Compared to hemoglobin from Asian elephants and humans, the woolly mammoth protein was much less sensitive to temperature changes. At low temperatures, it could still easily unload oxygen to tissues that needed it, whereas the elephant hemoglobins couldn't.
While more work is of course needed before the proteins can be incorporated into human blood, Ho says he's confident that the work will lead to a new generation of hemoglobin-based oxygen carriers.