Body heat loss through the transfer of heat to a substance or object in contact with the body is due to:

The correct answer, conduction, refers to the process of heat transfer through direct contact between materials. When the body comes into contact with a cooler object or substance, such as a cold surface or water, thermal energy moves from the warmer body to the cooler object. This occurs until thermal equilibrium is achieved. It is the fundamental principle of heat transfer in solids and is particularly significant in situations where the body is in direct physical contact with something else, causing the warmer molecules of the body to collide with the cooler molecules of the object, resulting in heat loss.

Conduction is particularly important in understanding how body temperature can be affected by surfaces a person contacts, which is critical in various contexts, such as during outdoor activities in cold environments. The efficiency of heat loss through conduction can be influenced by factors like the thermal conductivity of the materials involved and the surface area in contact.