The benefit of a cold bath or a cold shower before aerobic activity is that you increase the capacity of your body mass to absorb that excess heat.

So, you can cool the brain, you can have a cooling effect on the brain, by pouring water on on your head.

How to activate brown fat? If you are consistently exposed to cold, so if you live in the Arctic and you go out jogging in the winter, maybe that will increase the amount of brown fat you have. If you live in the tropics, maybe you have less brown fat. I don't know. I don't know of any studies which have looked into that.

Don't use screens within a couple hours of bedtime because screens are predominantly rich in blue light ... That affects your circadian system; that pushes off your circadian stimulus for sleep.

The primary sites of heat loss... are the palms of your hands, the soles of your feet, and the upper part of your face.

Most of the energy in our food is lost as heat. So, we are roughly about 20% efficient. So, of the energy that we take in in our food, about 20% of that can go into doing work, and the rest of it is lost as heat.