How is radiation defined in the context of heat transfer?

Radiation in the context of heat transfer is specifically defined as the transfer of heat without the need for direct contact between objects. This means that thermal energy can be emitted by one object and absorbed by another without any intervening medium or physical connection. An example of this is the heat you feel from the sun or a warm fire; the heat travels through space in the form of infrared radiation.

Other methods of heat transfer, such as conduction and convection, involve direct contact between materials or the movement of fluids. Conduction, for instance, requires a medium to transfer heat through contact, while convection involves the movement of heated fluids transferring heat. Radiation stands apart from these methods because it does not require a medium, allowing heat to travel through a vacuum. This fundamental understanding is essential in nursing, especially in scenarios involving body temperature regulation and understanding environmental heat effects on patient care.