In today's episode, Matt reveals how 1) your own temperature and, even more precisely, 2) the temperature of different parts of you, as well as 3) the temperature of your bedroom, can change how well or how poorly you sleep at night.

Matt describes the basic physiology of how your brain and body needed to drop their core temperature by about 1 degree Celsius, or about 2 to 3 degrees Fahrenheit, for a person to fall and stay asleep across the night. This is the reason why we will always find it easier to fall asleep in a room that's too cold than too hot because the room that's too cold is at least taking you in the right temperature direction for good sleep at night.

Matt teaches us that, ironically, one important way to drop your core body temperature is to warm up your extremities, specifically your hands and feet. He explains that it's one of the key ways your body regulates temperature.

To drive his point home, Matt points to research showing that if you gently warmed the paws of rats, it encourages the blood to rise to the surface of the skin of those paws, away from the core of the body. By emitting heat away from the body's center, it drops core body temperature rapidly, and as a result, the rats drifted off to sleep far faster than was otherwise normal.

Matt complements all this with a study in humans using a whole-body temperature sleeping suit, a little like wetsuit, but with tubes throughout that can warm or cool different parts of the body with warm or cool water.

In the first series of studies, researchers selectively warmed the feet and the hands by just a small amount, which caused a rising of the blood to the surface of the skin. As they warmed the body's extremities, the core temperature of the participants dropped, and the upshot was that these healthy individuals were falling asleep 20% faster than was normal.

In the second round of studies, even more remarkable, if you manipulate the temperature in this way in older adults, they will fall asleep 18% faster than typical, and insomnia patients will fall asleep a full 25% faster than usual with this same method.

The impact of temperature on sleep is therefore clearly significant, but there is even more to this thermal story, including how you can best wake up from sleep feeling alert, which is what Matt will discuss next episode.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic.

So, head on over to Athletic Greens and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts or feedback you’d like to share, please reach out on Instagram.

#13: Temperature - Part 1

The Matt Walker Podcast