Heat exhaustion is the body's response to an excessive loss of the water and salt, usually through excessive sweating.

Workers most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment.

Symptoms of heat exhaustion include:
• Headache
• Nausea
• Dizziness
• Weakness
• Irritability
• Thirst
• Heavy sweating
• Elevated body temperature
• Decreased urine output

First Aid
Treat a worker suffering from heat exhaustion with the following:
• Take worker to a clinic or emergency room for medical evaluation and treatment.
• If medical care is unavailable, call 999.
• Someone should stay with worker until help arrives.
• Remove worker from hot area and give liquids to drink.
• Remove unnecessary clothing, including shoes and socks.
• Cool the worker with cold compresses or have the worker wash head, face, and neck with cold water.
• Encourage frequent sips of cool water.

 From: cdc,gov
 Publishing date: 25/2/2017