What is the term for the transfer of thermal energy by the circulation or movement of a liquid or gas?

The process of transferring thermal energy through the movement or circulation of a liquid or gas is known as convection. This occurs when warmer areas of a liquid or gas rise, while cooler areas sink, creating a cycle of movement that facilitates the transfer of heat. In an esthetic context, understanding convection is important for procedures that involve the use of heated products or tools, as these techniques rely on effectively distributing heat through the client's skin or hair.

Conduction, on the other hand, refers to heat transfer through direct contact between materials, such as when a hot tool is applied directly to the skin. Radiation involves heat transfer through electromagnetic waves, which does not require a medium to travel through, like air or water. Insulation is not a method of thermal energy transfer but rather a means to prevent heat transfer, which is important in maintaining desired temperatures in certain esthetic applications. Recognizing these distinctions helps in applying correct techniques and ensuring client safety during treatments that involve heat.