What are the effects of high humidity on human health?

High humidity can significantly affect human health, primarily by leading to discomfort and heat stress. When the air is saturated with moisture, the body's natural cooling mechanism—sweating—becomes less effective because sweat evaporates more slowly in humid conditions. This can result in an increased body temperature and discomfort. In extreme cases, it may also contribute to heat-related illnesses such as heat exhaustion or heat stroke, as the body struggles to maintain a stable internal temperature.

The other options do not accurately capture the realities of high humidity. For instance, while dehydration is more commonly associated with low humidity or excessive heat, humidity itself can actually lead to sweating and fluid loss. Enhanced sleep quality is generally not a result of high humidity; in fact, many people find that humid conditions can disrupt sleep due to discomfort. Moreover, to suggest that high humidity has no significant effects overlooks the various ways it can impact physical well-being, particularly in vulnerable populations.