While working in a hot engine room, what is the cause of heat exhaustion?

Correct Answer: Option A — Loss of water and salt due to excessive sweating and inadequate water and salt intake.

Heat exhaustion in high-temperature machinery spaces results from the body's inability to maintain electrolyte balance. Excessive sweating depletes both water and essential salts. Without adequate replacement of these lost fluids and minerals, the body's thermoregulatory system fails, leading to the symptoms associated with heat exhaustion.