Dr. Matt Walker

There was also a great study unrelated from Australia.

They looked at insomnia patients and they put their hands or their feet in warm water.

And by doing that, it's a manipulation.

You can see how quickly their hands and their feet, what we call vasodilate, fill with blood.

Healthy people vasodilated very quickly in response to that warm water, meaning that their hands and their feet sort of had this red, or at least for my feet, they would be this red tone to them.

However, in the insomnia patients, they did not vasodilate anywhere near as well.

So once again, it suggests that when you have problems with sleep, part of the equation may be that you have impaired thermoregulatory ability.

And we do see this in insomnia patients.

So that's...

That was, I think, a brilliant causal manipulation.

The problem is that most of us don't have access to a sort of come to bed eyes thermal suit.

So what can we do as a concert?

Please don't cut that.

I get myself into terrible trouble, rightly so.

I should be punished.

You'll be all right.

What they did then was to say, well, okay, let's look at this.

is there something that we could do that's cheaper and more accessible to the general public?

And if you look, there's a literature that preceded that manipulation.

And it's so reliable that we now have a term for it in sleep science.