You might not think that your core body temperature has much to do with how well you sleep, but you’d be wrong. In fact, your core body temperature plays a critical role in regulating your sleep cycles. Temperature might be the most important factor in when you sleep and how well you sleep. Here’s how it works!
Your body’s natural sleep rhythm is governed by something called the circadian rhythm, which is basically a 24–hour internal clock that tells your body when it’s time to sleep and when it’s time to wake up. This internal clock is largely controlled by core body temperature and light exposure. When it’s dark outside, your body cools down and produces a hormone called melatonin, which makes you feel sleepy. When it’s light outside, your body warms up and produces a hormone called cortisol, which makes you feel alert. Temperature + light have a powerful control over our circadian rhythm.
So how does this all relate to sleep?
Well, as it turns out, your core body temperature plays a major role in regulating your sleep cycles. In general, your body temperature starts to drop a few hours before you go to sleep, and it reaches its lowest point right around the time you wake up. This dip in core body temperature is thought to be one of the main cues that tells your body it’s time to sleep. In fact, research has shown that artificially cooling the body can help people fall asleep faster and sleep more soundly. It is also the process of cooling the body that actually signals the brain to release melatonin.
What do I do with this information?
Luckily you can control your core body temperature easily. Taking a warm shower or bath an hour or two before sleep will lower your temperature. It does this because the heat will signal to the brain that it needs to start cooling the body rapidly. So while initially it may make you feel hot, after an hour or two you core body temperature will drop as the brain is trying to keep everything cool. You can do the opposite in the mornings to feel more awake and ground your circadian rhythm. Taking a cold shower or bath in the morning will wake you up, and will raise your core body temperature, which is exactly what you want in the mornings.
So if you’re looking for a way to improve your sleep, one of the best things you can do is to take a hot shower or bath and make sure your bedroom is cool and comfortable. This will help your body reach its ideal sleeping temperature, and as a result, you’ll sleep better and feel more rested when you wake up. Once you are up you can use a cold shower to wake up even faster.