What does radiation refer to in terms of heat loss?

Radiation refers to the loss of heat in the form of infrared rays, which is an essential concept in understanding how heat is transferred. Unlike conduction, which requires direct contact between materials for heat transfer, or convection, which involves the movement of fluids, radiation allows heat to be emitted through electromagnetic waves. This process does not rely on any medium, meaning heat can be lost through radiation even in a vacuum.

In the context of thermal regulation in the human body, radiation plays a significant role, especially when the body temperature exceeds that of the surrounding environment. By emitting infrared rays, the body can effectively lose heat, contributing to maintaining a stable internal temperature. Understanding radiation is crucial for both physiological processes and applications in fields such as engineering and environmental science.