August 17, 2022 3 min read
Do you ever wake up sweaty in the middle of the night? Or roll out of bed in the morning only to discover you’ve tossed your blanket across the room? Do you perhaps even feel like you sleep worse in the summer? Maybe none of these things have ever happened to you, or you just don’t really think about it,, but a sleep geek like me thinks of all sorts of weird and mundane things. Indulge me a little bit and I promise you'll get some useful information by the end of this email.
A lot of people ask me "what happens when you sleep?" My answer is usually something like; "what happens when you're awake?" I say this partly because I'm a bit of a smart aleck, and partly to point out that sleep isn't some collapsed state of disanimation. Your biochemistry is at least as active while you are asleep as when you're awake, and your brain is definitely just as active--just in different ways. Interestingly, one physiologic change that happens when you fall asleep is that your body temperature drops about one degree Fahrenheit. There are several factors involved, but one obvious thing is that you aren't generating any heat by moving your muscles. You should not "feel" hot while you're sleeping, and I'm not talking about your estimation of your sexual attractiveness.
We evolved to sleep when the sun was below the horizon, and the land and air were cooler. You can't escape evolution. You are not just on this planet, you are part of it. Research has shown the ideal sleep temperature to be about 65 degrees Fahrenheit, and the closer you get to that number, the higher the quality of your sleep. So your body doesn’t just cool itself down, it expects the world around you to be cooler as well. In fact, it demands it.
As I alluded to earlier, there are thousands of things changing around in your brain and body's chemistry while you are asleep and these things need to be able to run their natural course for you to get quality sleep. While you're sleeping there are periods where your muscles are paralyzed. This is necessary in order for your brain to do its repair/prepare work. If your skin or body feels too hot, your sleep will be interrupted so that you can move to a cooler spot, remove covers, roll-over etc. Afterwards, your brain and body have to do a bunch of extra work to get you back to the sleep stage you need to be in to continue the cycles of activity that define quality sleep. You may not perceive any of this activity; to you you’re not even “awake,” but your sleep is nonetheless interrupted any time your body needs to move to adjust your temperature.
There are other reasons that you may need to move around, and I'll cover those in separate emails. But, the lesson for today is that you are better off being a bit too cold than being too hot while sleeping. I know running the A/C is expensive these days, and they can be noisy too, but You owe it to yourself to get the best sleep you possibly can.
You are an intelligent animal (and the improvement in your sleep will make you an even more intelligent animal). You can figure out how to keep yourself cool at night if you put your mind to it. So, turn up the A/C, use fewer blankets or covers, sleep nude, take a cold shower before bed, open windows, buy a fan . . . do whatever you have to not be so damn hot at night. You have nothing to lose and everything to gain. Once you get into a groove, you'll love it, and you'll be glad you read this email.
For even better sleep, check out my all-natural sleep supplement that I designed to help anyone get higher quality sleep.