Heat stroke Exposure to high environmental temperatures can lead to following conditions ? I . Heat fatigue - Performance of a person decreases due to high environmental temperatures. The person gets tired early d/t high temp. 2. Heat cramps - these are painful spasms of voluntary muscles following strenous work in hot conditions, These cramps are caused by loss of water and salt from profuse sweating. 3. Heat syncope (heat exhaustion, heat collapse) - It is a condition of collapse without increase in body temperature, following exposure to hot and humid atmosphere. - On examination,. face is pale, .skin cold, the temperature subnormal - The pt. usually recovers when placed at rest. Death is unusual and may occur d/t hea failure. 4. Heat stroke - (heat hyperpyrexia, sub stroke) - It is due to impairment of body's heat regulating mechanism caused by failure of cutaneous circulation & sweating, following prolonged exposure to hot, humid conditions. - The onset is usually sudden with sudden collapse and loss of consciousness. Predominant symptoms may also be seen (i.e. headache, nausea, vomitting, dizziness, mental confusion, muscle cramps, excessive thirst, excessive desire to micturate) - The skin is dry, hot and flushed with complete absence of sweating - Body temperature rises as high as 43degC (hence k/a hyperpyrexia) when body temp. rises above 42degC vasodilation occurs with decrease in blood volume leading to circulatory collapse and cardiac failure. - Delirium and convulsions may precede death. - Moality rate in this condition is relatively high. - Fatal period varies from few minutes to 3 days.