What is Heat stroke (also called Sun stroke)

This is a quick reference for general public awareness about Heat stroke (also called Sun stroke). I compiled this, as many people, even in educated families, didn’t know about it and barely saved from it, during recent heatwave in Karachi.


Heat stroke results from prolonged exposure to high temperatures — usually in combination with dehydration — which leads to failure of the body’s temperature control system. The medical definition of heat stroke is a core body temperature greater than 105 degrees Fahrenheit, with complications involving the central nervous system that occur after exposure to high temperatures. Other common symptoms include nausea, seizures, confusion, disorientation, and sometimes loss of consciousness or coma.

Symptoms of Heat Stroke:

The hallmark symptom of heat stroke is a core body temperature above 105 degrees Fahrenheit. But fainting may be the first sign.
Other symptoms may include:
• Throbbing headache
• Dizziness and light-headedness
• Lack of sweating despite the heat
• Red, hot, and dry skin
• Muscle weakness or cramps
• Nausea and vomiting
• Rapid heartbeat, which may be either strong or weak
• Rapid, shallow breathing
• Behavioral changes such as confusion, disorientation, or staggering
• Seizures
• Unconsciousness

People most at risk of heat-related illness:

Anyone can suffer from heat-related illness, but those most at risk are:
• People over 65 years, particularly those living alone or without air conditioning
• Babies and young children
• Pregnant and nursing mothers
• People who are physically unwell, especially with heart disease, high blood pressure or lung disease
• People on medications for mental illness.

Causes of heat stress and heat-related illness:

There are many factors which can cause heat stress and heat-related illness, including:
• Dehydration – to keep healthy, our body temperature needs to stay around 37°C. The body cools itself by sweating, which normally accounts for 70 to 80 per cent of the body’s heat loss. If a person becomes dehydrated, they don’t sweat as much and their body temperature keeps rising.
• Lack of airflow – working in hot, poorly ventilated or confined areas.
• Sun exposure – especially on hot days, between 11am and 3pm.
• Hot and crowded conditions – people attending large events in hot or crowded conditions may also experience heat stress that can result in illness.

Heat stroke – treatment:

Heat stroke is a medical emergency and requires urgent attention:
• Call for an ambulance.
• Get the person to a cool, shady area and lay them down while you’re waiting for emergency medical help.
• Remove clothing and wet their skin with water, fanning continuously.
• Do not give the person fluids to drink. (You can give fluids in case of heat exhaustion.)
• Position an unconscious person on their side and clear their airway.