As a subject is soaked down additional bystanders can fan the subject thereby aiding in the cooling process. The arid canyon environment and altitude combine to accelerate the loss of water quicker than most people expect. Using thirst as a gauge as to when to drink is inaccurate. By the time you notice that you are thirsty you are already dehydrated. Heat exhaustion victims become tired, fatigued, have either pale or flushed skin and may be vomiting.
Vomiting hastens the dehydration of the patient.
If they are able to tolerate oral fluids have them take small sips of water rather than large gulps, the latter of which they will typically vomit back up. Provide them with prolonged rest and oral rehydration. This heat-related illness is caused by an imbalance of electrolytes in the body. Field treatment will not typically reverse this condition and the patient is in need of hospitalization. Assist the patient with maintaining their airway.