12 Things That Happen to Your Body When It’s Freezing

Your blood vessels constrict

one woman walking on bridge in city park with snow falling and back to camera

Your body is built to always maintain a stable core temperature of 37 degrees Celsius (that’s 98.6 degrees Fahrenheit). When the temperature in your environment drops to freezing cold, thermoreceptors in your skin sound the alarm, alerting an area of the brain called the hypothalamus, which acts like a thermostat dedicated to maintaining that 37 degrees equilibrium, according to Robert Kenefick, PhD, research physiologist at the U.S. Army Research Institute of Environmental Medicine. One of the first actions the hypothalamus takes: It tightens the blood vessels in your arms, hands, feet, and legs. “Blood delivers heat to the skin,” says Gordon Giesbrecht, PhD, professor of thermophysiology at the University of Manitoba in Canada. “If you decrease blood flow to the skin, you decrease heat loss from the skin.”

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