Fatigue and weakness
Tachycardia
Anxiety
Muscle cramps
Headache
Irritability
Vertigo
Syncope
Prolific sweating
Hypotension
Nausea
Cold, pale, clammy skin
Chills
Piloerection
Mental deterioration

As with heat exhaustion
and:

Cessation of sweating
Hot and dry skin
Seizures
Loss of consciousness
Death

As with heat exhaustion
and:

Continuation of sweating
Incoherent speech
Acute renal failure
Lactic acidosis
Rhabdomyolysis
Hyperuricemia
Hyperkalemia
Seizures
Loss of consciousness
Death