Sleep Temperature

Sleep hot or cold? Whether temperature fluctuations are internal or external, finding the right balance can be a challenge.

Research tells us that the ideal bedroom temperature for sleep is around 65 degrees Fahrenheit. At this temperature, our bodies are most likely to remain “thermally neutral” with a normal amount of bed clothes and bedding. Thermally neutral means that our body doesn’t have to do anything to create heat (shiver) or shed heat (sweat) to compensate for being too cold or warm.

Near our habitual bedtime, our internal core body temperature begins to drop. In the morning the reverse happens to help us wake naturally. This is an important physiological process that promotes deep continuous sleep. It’s important to permit this to happen; otherwise our ability to fall asleep quickly and attain deep sleep is hampered. That’s why vigorous exercise or large meals too close to bedtime are discouraged—both greatly elevate body temperature and interfere with sleep.

There are primarily two ways in which the body cools off for sleep. First, when we lie down to sleep, our metabolism slows down and our mere inactivity significantly diminishes the generation of heat. Secondly, blood vessels in our extremities (hands, feet, and head) specifically designed to release heat quickly dilate to facilitate rapid heat loss. A warm shower near bedtime accelerates this heat loss—the body senses the warmth and compensates by increasing natural heat loss to cool off.

Ironically, as our internal body temperature falls we many times feel hot at night as all this released heat through our skin “pools” around our bodies. Most of us can recall turning the pillow often to find the “cool” side!

We can compensate for these fluctuations with temperature balancing efforts. Cool bedrooms are a good example—heat likes to travel from high to low temperature locations. Fans can accelerate that by dispersing warm air around our skin.

Individuals sharing a bed may have different tolerances to these temperature variations. Dual weighted blankets and comforters where one side is significantly lighter than the other are ideal for such couples.

Another excellent alternative is a new temperature balancing material found in our In Balance™ Bedding Solutions that continually reacts to changes in skin temperature by absorbing excess heat, keeping it away from the skin early in the night and then releasing it back as the body wants to warm up early in the morning thus maintaining thermal neutrality. This material can be part of the mattress itself, or in any of the bedding collection (sheets, mattress pads, blankets, pillowcases—even pajamas!) Originally developed for NASA spacesuits to deal with temperature swings in space, it’s an exceptional example of a new technology to improve sleep, too!

The In Balance mattress pad is the greatest. I would recommend it to anyone that sleeps warm or may have hot flashes.

C.F.
SLEEP NUMBER 55