Better Sleep is Cool
December 19, 2017
There are many environmental factors that can affect the quantity of quality sleep our bodies need for us to function at our best. Most experts in the sleep field agree that our bedroom should be like a cave…dark, quiet and cool. But though most people realize their need to control the environment of their bedroom, few understand the life changing consequences the bed can make.
Many of us know that the cooling of the body actually facilitates our ability to fall asleep. That is why many sleep experts recommend a hot bath or shower 60 to 90 minutes before bedtime, so the body can be in a cooling down state while we are trying to fall asleep. But many do not know that the ability for the body to remain cool throughout the night greatly effects our ability to remain in the deep Slow Wave and REM sleep we need to rejuvenate both our body and mind. Waking during the night because of body temperature spikes is epidemic in the general population but is exacerbated by the aging process, making baby boomers even more the victim of this sleep-robbing phenomenon.
For centuries most people slept on the ground or in trees, on stone or wood surfaces, all of which were cooling in their interaction with the body. Then came thin mattresses over rope ties (which had to be retightened periodically to keep from sagging, therefore the term “sleep tight”) also creating air flow around the body. Later innerspring mattresses were introduced. Their open effect with minimal padding, usually of some sort of fiber in the old days, also facilitated airflow, thereby allowing the body to stay cool during sleep.
Then came the advent of a new type of material for mattresses, visco elastic foam, better known as slow recovery or memory foam. I know the first time I saw a sample of this product in the 1980’s I was impressed with the ability for the product to conform, but in testing was turned off by the product’s reaction to temperature changes. You may know that most pure memory foam actually becomes softer with heat, conversely being as hard as a rock when exposed to cold. This interaction to temperature’s greatest detriment, though, is that it facilitates the holding of heat, thereby making many memory foam beds sleep hot as the night progresses. A build up of heat disrupts sleep, particularly during the times of the deep, restful sleep our bodies need.
Many manufacturers of memory foam mattresses have used “gel infusion” as their way of supposedly lessening this warming effect, saying that the gel wicks away the heat. But where does this heat go? It stays right there in the mattress as a heat holding device. Even if gel was the answer, most gel infused memory foam mattresses today use what I call “essence of gel” as the particles are too small and way to spread out to have any real cooling properties. The only way to truly keep a mattress cool during the night is to facilitate airflow and to have cooling properties next to the skin, as it is ambient skin temperature which really can affect sleep quality.
Therefore I have always known that memory foam is best used as the conforming support layer of a good mattress, not as the initial layer next to the skin. Though in a store many sales people want to show you the hand print of a slow recovery bed, in my opinion this exact hand print is what can be the problem as it assures that heat will be trapped during the night. Of course many manufacturers now tout the advent of faster recovery memory foam. In my view this is arguing that “faster recovery slow recovery foam is better than slow recovery slow recovery foam.” Doesn’t make much sense to me.
Instead look for a product, like the Snuz mattress, that has the ability to breathe as you naturally move during the night, dissipating the heat through engineered air channels. Also look for a cooling mattress cover, which can be your first defense against an increase in ambient skin temperature during the night. And of course try to keep room temperature in the 60’s using sheets and sleep clothing that do not facilitate heat build up. Add this to a quiet and dark room and you will give yourself the best chance of getting the quantity of quality sleep you need and deserve.