What is sunstroke?

unstroke also known as heat stroke is an acute, life-threatening condition in which the body’s heat-regulating system fails, due to prolonged exposure to high temperatures, excessive production of heat or commonly a combination of the two. In this condition the body is unable to lose heat adequately in order to return to its normal temperature. If the body temperature rises to very high levels, it can damage major organs.

Sunstroke can be preceded by heat exhaustion, when excess loss of fluids and salt in sweat results in marked weakness. Heat exhaustion becomes sunstroke when the body can no longer maintain a normal body temperature. Heat exhaustion may be accompanied by heat cramps: sudden painful muscle spasms in the arms or legs, and sometimes the abdomen.

Causes of sunstroke

In a hot environment, your body rids itself of excess heat through increasing blood flow to the skin, sweating and breathing out warmed air. However, these mechanisms can sometimes be overwhelmed, leading to heat-related symptoms, which, if left untreated, can lead to sunstroke.

Sunstroke usually occurs after exposure to high temperatures, for example from working in an extremely hot environment, especially one to which you are not used to; exercising too strenuously, particularly in the summer; or when you have a high fever associated with illness. Humid weather also renders the cooling mechanism of sweating less effective. Overdressing and overeating can also be contributing factors.

The primary cause of symptoms is loss of sodium and chloride (which make up salt), rather than the amount of water.

Liquids help to cool us down by allowing the body to produce sweat. You can lose large amounts of body fluid in the form of sweat without noticing any effects, but at a certain point the body will reserve the remaining fluid for vital functions, and stop sweating. The body’s core temperature shoots up, and cells start dying.

Sweat evaporates more rapidly in dry weather, cooling the body more efficiently than in humid weather. When working in humid conditions, the core temperature rises more rapidly. This is why weather forecasts add a humidity heat factor to represent how you will actually feel outdoors.

Symptoms and signs

of sunstroke

The symptoms of sunstroke may include hot and dry skin. There’s usually no sweating and the body temperature rises rapidly to 40 degree centigrade or higher. The skin seems flushed rather than pale or purple. Other symptoms may include hyperventilation (rapid, shallow breathing); rapid, bounding pulse (alternates between a higher intensity than normal, then disappears quickly); headache; muscle cramps, dilated pupils; loss of consciousness; convulsions; lethargy or stupor (reactions become extremely slow and sluggish). Signs of mental disorder may include incoherent speech, disorientation, confusion, aggressive speech or behaviour, agitation and hallucinations.

Treatment of sunstroke

Treatment of heat-related illness depends on its severity. But if you think someone has sunstroke, call an ambulance or take the person to hospital immediately. The primary treatment goal is to lower the elevated body temperature as quickly as possible. So, while you’re waiting for medical help, give first aid as follows:

Remove the person’s clothing and immerse the body in a cold water bath. If your water supply is limited, cooling the head and neck becomes the priority. Place ice packs (if available) at the neck, armpits and groin. Fan the person with a newspaper, towel or electric fan to increase air flow and evaporation. Massage the extremities (arms and legs) to encourage the return of cool blood to the brain and the core of the body.

If the person is conscious, encourage him or her to sip water or a soft drink. If the mental state is impaired, it may be impossible to get the person to drink. Continue with external cooling in the hope that the person will recover sufficiently to begin drinking.

Who is at risk?

Anyone exposed to high temperatures is at risk of sunstroke, but the young children and elderly people are at particularly high risk and must take special precautions to avoid hot, poorly ventilated places and exertion in hot weather.

Sunstroke also affects people with certain chronic conditions such as arteriosclerosis, congestive heart failure and  diabetes mellitus. Also people taking part in certain types of sporting activities, such as long-distance running or cycling are at a high risk of sunstroke.