What condition results from excessive loss of fluids through sweating and exposure to heat?

Heat exhaustion occurs as a result of excessive fluid loss through sweating and prolonged exposure to high temperatures. This condition is characterized by symptoms such as heavy sweating, weakness, dizziness, and a rapid pulse, which are due to the body's attempt to cool itself in an environment that exceeds its capacity to maintain a safe internal temperature.

When the body loses too much fluid and electrolytes, it can no longer effectively regulate temperature or maintain blood circulation, leading to complications if not treated promptly. In such cases, the individual typically requires rest, rehydration, and cooling down to recover.

Other conditions listed in the options refer to different mechanisms: heat cramps involve painful muscle contractions often due to electrolyte loss, heat stroke represents a severe form of hyperthermia with central nervous system dysfunction, and hypothermia occurs from excessive cold exposure, not heat. Hence, the context of dehydration and heat exposure uniquely identifies heat exhaustion as the correct condition resulting from excessive fluid loss.