Which of the following conditions does NOT result from heat illness?

Sunburn is a condition that occurs due to overexposure to ultraviolet (UV) radiation from the sun, leading to damage of the skin cells. While sunburn can certainly be a painful and harmful condition, it is not classified as a heat illness, which typically involves the body's inability to regulate temperature and can affect internal systems. Conditions such as heat stroke, heat exhaustion, and heat cramps are all characterized by the body's response to excessive heat and physical exertion, where the body becomes overwhelmed by heat and cannot cool itself effectively. Therefore, sunburn is distinct from these other conditions, as it does not arise from the same physiological processes associated with heat illness.