A drop in core body temperature is necessary for falling asleep and staying deeply asleep.

“And as your body temperature drops by one to three degrees, and here I'm referring to your core body temperature, not your shell body temperature, you will start to get sleepy and to transition into sleep and to maintain sleep throughout the night.”

“Similarly, you should try and make your sleeping environment pretty cool, if not cold. Now, that doesn't mean you need to be cold while you're asleep. You can get under as many blankets as you need, but it's a good idea to make your sleeping environment cool. In fact, drop the temperature in that sleeping environment by at least three degrees and you'll be happy that you did.”

“That is, dropping your core body temperature one to three degrees gets you into sleep and helps you stay asleep.”

“It turns out that your body temperature and your ability to fall and stay asleep are very closely related. If your body does not drop by one to three degrees, you are simply not going to get into deep sleep or stay in deep sleep.”

“Temperature is another tool or lever. Turns out that when your body is cooling down, you have a greater tendency to fall and stay asleep.”

“Turns out that when your body is cooling down, you have a greater tendency to fall and stay asleep. In fact, every night when you actually sleep, your body is dropping by one to three degrees and that drop in temperature is required. It's like a gate that your body has to go through in order for you to get into sleep. And in fact, the converse is also true. If your body heats up by one to three degrees or so, you will wake up.”

“That is in order to fall asleep and stay deeply asleep throughout the night, our body temperature needs to drop by about 1 to 3 degrees. And conversely when we wake up in the morning, that is in large part, because of our body heating up by 1 to 3 degrees.”

“in order to fall asleep at night your body needs to drop by about 1 to 3° in terms of core body temperature and waking up involves a 1 to 3 degree increase in core body temperature”

“Therefore, controlling the temperature of your sleeping environment is absolutely key.”

“Conversely, in order to wake up each morning and feel refreshed, your body temperature actually has to increase by one to three degrees.”

“But what many people don't realize is that in order to fall and stay asleep, your core body temperature has to drop by about one to three degrees.”

“in order to fall asleep and stay deeply asleep throughout the night your core body temperature needs to drop by about 1 to 3° conversely in order to wake up in the morning feeling refreshed and ready to go your core body temperature needs to go up by about 1 to 3°”

“temperature we've spoken about that a little bit you need to get cool to get to sleep and it's the reason that you will always find it easier to fall asleep in a room that's too cold than too hot”