Originally published in 2000
Dehydration and the Pilot: 3 Stages of Heat Exhaustion
Transition from the one to the other can be very evident, hardly noticeable, or not evident at all.
Heat stress (body temperature, 99.5 – 100 F) reduces:
Performance, dexterity, and coordination
Ability to make quick decisions
Alertness
Visual capabilities
Caution and caring
Heat exhaustion (101 – 105 F) symptoms:
Fatigue
Nausea/vomiting
Giddiness
Cramps
Rapid breathing
Fainting
Heat stroke (> 100 F) symptoms:
Body’s heat control mechanism stops working
Mental confusion
Disorientation
Bizarre behavior
Coma
Source: FAA Aviation News