Heat is transferred in 3 ways Conduction, Convection & Radiation.
Conduction through solid material or gas: the better insulating the material, the less the conduction
Heat "travels" through air movements because of temperature and density gradient. Hot air moves up and heat dissipates. The stiller the air, the less the convection
Each material absorbs or emits thermal radiations depending on its temperature and its emissivity .Heat exchange is function of propagation media (vacuum or air) When radiation is absorbed or reflected , there is less thermal transfer.