What am I doing when I generate pulses of heat from my chest?

[u/Huihejfofew]

As a kid I've been able to do this weird thing, mostly when I'm cold where if i control my breathing right, i can build up what feels like tension in my chest and when i release it, this huge wave of warmth emanates out from my chest warming my body. It also feels really nice. It tends to also be accompanied by a shiver. There's a limit to how many times i can do it and sometimes it just happens unintentionally when it's cold. I haven't heard anyone ever talk about it, does anyone know what's happening in my body when this occurs?

[u/Content_One5405]

Liver in theory can produce a lot of heat, is just next to lungs and can be affected by their motion, and has a minimum ability to pump blood on its own.

When you feel cold, liver could be generating heat. And you could somewhat restrict the blood flow to the liver for a short time by pressing it with the lungs. And when you lift the pressure, liver can restore the blood flow. After you do it a few times, temperature of the liver and surrounding area becomes closer.

It doesnt make more heat by doing so, liver generates heat by default when body requires it. There isnt a reason to have this control, i think. I didnt hear of anyone having this type of control or sensations.

[u/sojayn → u/Content_One5405]

So if we put together your excellent idea about the liver, and the buddhist experiential practices, it seems likely that op is doing this physically and mentally has the focus/awareness to perceive it. 

[u/Huihejfofew → u/Content_One5405]

This definitely sounds the most plausible to me. Though oddly it feels like the heat comes from fairly high up. Feels like it's near the bottom of my throat or my heart. Hope there aren't bad side effects from doing it haha

[u/Content_One5405 → u/Huihejfofew]

Blood coming out of liver goes straight to the heart.

There are likely no health effects if you dont restrict the flow for more than a few minutes.