The diving reflex, activated by submerging the body in cold water, is a survival system that preserves oxygen and prevents rapid hypothermia.

“You can put your face under and activate the so-called dive reflex, which also makes the tolerance of cold easier believe it or not.”

“so when when you activate your uh diving response you will slow down your um your oxygen consumption in your body and that is because the body tries to preserve um oxygen so you will not get hypothermic too fast so it's kind of like a survival system in your body”

“when you do that you have an activation of your diving response and uh that's going to slow down the you can say the the consumption of oxygen also in your body so that's going to slow down your heart rate”

“if you hold your breath and put your face in a bowl full of cold water, your body responds as if you're diving. And what that means is that your heart rate slows down, your blood vessels and your extremities constrict because, you know, your fingers will be okay with a little bit less oxygen, but your brain really needs that oxygen. So it's keeping the blood, central, where you need it the most.”

“When we put our face in the water we get this malean dive reflex and the deeper we go the more the heart slows down the more the blood wraps”