Another reason why it’s important to keep cool at night: We need a respite from sweating, which can exacerbate dehydration.
Normally, sweating dissipates body heat. But when it is too hot and humid for sweat to effectively evaporate, a person can overheat. When that happens, muscles and enzymes can stop working and eventually internal organs may shut down. Victims risk losing consciousness, suffering seizures or losing the ability to breathe — all potentially fatal conditions.