When the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. The result can be heat stroke or heat exhaustion. The risk for heat-related illness and death is higher for infants and the elderly, whose internal thermostats do not regulate body temperature well. Heat-related illness and death are readily preventable, Dr. Raymond said. Sunburn interferes with the body's job of heat dissipation, and too much sun exposure is a risk factor for skin cancer.
Fans can be a source of relief, but the higher the humidity, the less cooling relief they provide.
Air movement at high levels of humidity can increase heat stress. Heatstroke, the most serious heat-related illness, is a medical emergency characterized by a body temperature of 105 degrees F or greater. Symptoms include hot dry skin, rapid heartbeat, shallow breathing, disorientation, delirium, and coma. An individual suffering from heat stroke should be moved into the shade or into an air-conditioned location and emergency medical assistance should be summoned. Heat exhaustion is a milder form of heat-related illness that can develop following exposure for several days to high temperatures.