see the particle model of matter

If heat is kinetic energy, then a lack of kinetic energy is cold

Weirdness .... is fire alive?

probability cloud of matter

transferring energy through:

conduction - direct contact (as much as you can with the particle model)

convection - flowing via a fluid or gas. Density explaining much of this movement.

Radiation - infrared

The ability to trap air is insulation. Goose down is the best - when dry.