The human organism responds to radiated heat with a particularly pleasant feeling. It is physiologically beneficial and soothing.
Since prehistoric times humans have utilised and enjoyed radiated heat. It is transmitted by electromagnetic waves in the infrared range. Radiated heat travels through air without loss and without heating this. Not until it encounters solid bodies like walls, objects and also people does it generate heat. This effect is familiar to everyone from sunny winter days.
Even when the air is very cold you can feel the warm rays of the sun on your skin. It makes you feel a temperature that is higher than the actual air temperature. This explains the great benefits and the sustainability of radiated heat.