Heat is transferred by electro magnetic waves, for the case with fire it's infra red waves.
fire
Because it heats them up.
Nervous system
A fire is radiation.
Passive Immunity is when the body receives antibodies from another organism.
The right atrium of the heart receives oxygen-poor blood from the body.
It is either on fire or very hot as passing through the atmosphere heats it up a graet deal.
Sweat is water
evaporation
your brain
Well During sex or other such activities... the inside of the body heats up... and gives the term of hotness and wetness...
Your body receives hydration.