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