Core body temperature is 37°C. The primary mechanism of heat loss at rest in a thermoneutral environment (25°C) is:

• A Evaporation of insensible perspiration
• B Radiation (infrared radiation from skin to surroundings) ✓
• C Convection via circulating air over the skin surface
• D Conduction to solid objects in contact

Explanation

At rest and in a thermoneutral environment, radiation accounts for approximately 60% of total heat loss from the body. Radiation involves emission of infrared electromagnetic waves from the skin surface to surrounding cooler objects, without direct contact. Evaporation (insensible + sensible sweat) contributes about 25%, convection about 15%, and conduction is negligible in most clinical settings. During exercise or in very hot environments, evaporative cooling (sweating) becomes the dominant mechanism.

Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.