Ben Greenfield

That's the one I keep at like 33 degrees.

That one's called the Morosco.

This is the one that I was in this morning, just swimming underwater laps.

So this is like an endless pool that I have in my pool house in the backyard.

I don't put ice in it, but I just don't keep it warm.

decrease in risk of certain brain diseases based on what you described, the fact that it can allow for almost like a sealing of the blood-brain barrier, allowing less toxins and metals and inflammatory compounds to cross over into neuronal tissue.

So this one's at about like 45 degrees.

It fluctuates based on the season.

That over there is the hot tub, so I can go back and forth from the cold pool to the hot tub.

But I'm a huge fan of cold.

I raced Ironman triathlon for 12 years.

I did races all over the planet, and I was doing cold thermogenesis before I even knew the benefits of it.

You know, I'd get out of the water freezing, and I'd feel great, and my mental willpower would be higher the rest of the day, and it was pain-killing, and it was mood-boosting.

Very similar to how a good night of sleep could help with that.

Or very similar to how proper mineral intake, particularly magnesium, can help with that.

But I didn't realize until I actually started to study up the science of it for my book, Boundless,

Fish oil can help with that.

Well, it turns out that cold, specifically the process of getting the head and neck and face cold, is fantastic for brain function.

how big of an impact it has on the release of feel-good chemicals, on decreased inflammation, on the conversion of metabolically inactive white adipose tissue into metabolically active brown fat that you have to make to generate heat to warm yourself back up.

So huge variety of benefits.