Turning up heat may be costing you sleep in winter

As winter cold intensifies, many people respond by cranking up indoor heating. But sleep specialists warn that excessive warmth can be one of the biggest obstacles to a good night’s sleep, as it interferes with the body’s natural temperature regulation. When room temperatures rise too high, peripheral blood vessels dilate excessively, preventing internal heat from being released. As a result, the body’s core temperature remains elevated, making it harder to fall asleep. Core body temperature refers to the temperature maintained by vital internal organs such as the heart, lungs and liver. For healthy sleep, core temperature needs to drop by about 0.5 to 1 degree Celsius before bedtime. This cooling process also promotes the release of melatonin, the hormone that induces sleep. Overheating suppresses this natural decline, delaying the onset of sleep. Experts recommend keeping indoor temperatures between 18 and 22 degrees Celsius, with humidity levels maintained at 40 to 60 percent. Sohn Yeo-ju, a professor of family medicine at Ewha Womans University Seoul Hospital, said, “When in