What is Heat Radiation? If we stand before the fire, we feel hot. The heat comes to our body neither by convection nor by conduction (air is a bad conductor of heat). The heat comes to our body by radiation. It does not require a medium for heat transfer. For conduction and convection, an intervening medium is necessary because molecules of the medium play an important role. For radiation, molecules are not required. Even in a vacuum, heat travels from a hot body to cold body. The heat of the sun (hot body) warms the earth (cold body), and yet … Continue reading Heat Radiation