Hi there, it's Matt Walker here and welcome back to the podcast. Now I'm sure you've heard of that

the phrase where people will tell you, cold hands warm heart, so the saying goes.

In truth, I don't know of any scientific data to back that up,

but there is scientific truth however in the statement

warm feet good sleep and we'll get to that because for the next two episodes we're talking all about temperature.

How your own temperature and specifically the temperature of different parts of you

and the temperature of your

bedroom can change how well or how poorly you sleep at night.

What we discovered many years ago was that your brain and your body

need to drop their core temperature by about

one degree Celsius or about two to three degrees Fahrenheit in order for you to

fall asleep and for you to stay asleep across the night.

And this is the reason why you 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 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.

And we've seen this time and time again, so I can bring you into my sleep center, and upon

arrival I will insert a rectal probe so that I know exactly what's happening with your core body temperature.

You may think that that sounds like no fun for you, but I can also say that it is far from the most desirable thing to

insert as a scientist. The things that we do for research, let's just say that the two of us will have slightly less dignity

at the end of that procedure. And after inserting the rectal probe, I will then remove all sense of time.

There will be no clocks, no windows, no phone, no computers, and then I'll simply ask you to go to bed at whatever time you wish,

whenever you feel most sleepy.

And even though you have no idea of what your core body temperature is, sure enough, you

will say that you hit your peak sleepiness right at the steepest decline in your core body temperature that I'm

...