Maybe make small combustions in my heart or blood to speed up blood flow or get rid of blockages, could also work to incinerate poisons, not really a good idea unless your character has good internal defenses.

you can warm yourself and eliminate viruses and diseases, you can heat a part of the body and accelerate regeneration, you can drink cold drinks and warm inside you or you can heat on contact, you can melt metal pieces and make life easier in small ways, you can burn the puppets and poop and don't go to the bathroom (darken or burp), in winter stay warm and so on

How do you accelerate regeneration with micro explosions?

@Nicholas8293 it has self-combustion, so it heats up, the body in contact with the heat regenerates faster

I thought that was only for cold