The strange animals that control their body heat
In 1774, British physician-scientist Charles Blagden received an unusual invitation from a fellow physician: to spend time in a small room that was hotter, he wrote, “than it was formerly thought any living creature could bear.”
Many people may have been appalled by this offer, but Blagden was delighted by the opportunity for self-experimentation. He marveled as his own temperature remained at 98° Fahrenheit (approximately 37° Celsius), even as the temperature of the room approached 200°F (about 93°C).
Today, this ability to maintain a stable body temperature—called homeothermy—is known to exist among myriad species of mammals and birds. But there are also some notable exceptions. The body temperature of the fat-tailed dwarf lemur, for example, can fluctuate by nearly 45°F (25°C) over a single day.