A 50-degree fall day sends you running for a down jacket, while a 50-degree day in spring feels almost balmy. What’s up with that? Your body has an innate ability to “acclimatize” to colder temps—a skill scientists have recognized since a groundbreaking 1961 study.
For that month-long study, a U.S. Army researcher exposed 10 nude men to temperatures in the low 50s for eight hours a day. Not surprisingly, the poor study subjects did a lot of shivering—which is the body’s quick-fix way to generate heat. But by day 14, the men had mostly stopped shivering, and their bodies seemed to be making heat some other way.
