Too hot to handle

Soaking up some sunshine can feel great. Overheating feels horrible. In fact, it can be life threatening. Here’s what you need to know from the get go.

By Georgia South

As a car engine that overheats can seize and stop working, so can your body. Heat stroke or sun stroke is a dangerous condition that happens when the body continues to heat up and can’t cool itself down. If not treated immediately, internal organs can be damaged, and the person could go into a coma and die as a result. Heat stroke is often preceded by heat exhaustion and muscle cramps from excessive sweating and fluid loss because of overheating.  

WHAT CAUSES HEAT STROKE?

Excessive exposure to the sun or heat, along with dehydration, are the usual and obvious causes of heat stroke, but it can also be caused by medication, like some cancer treatments, and certain types of general anaesthetic. A very hot and humid environment is the usual cause of heat stroke, and this would be exacerbated by strenuous exercise, hard physical labour or a fever. Quite surprising to know is that overeating and drinking alcohol may also contribute to the onset of heat stroke.

Our normal body temperature is between 36°C and 37°C. When you’re too hot, your body first tries to cool you down by increasing blood flow to the skin, sweating and breathing out hot air. If blood temperature rises above normal, the hypothalamus in the brain instructs blood vessels to increase in size to allow more blood to flow to the skin and to be cooled by the outside air. But if the surrounding air is too hot or too humid for sweat to be evaporated to cool the body, the body’s cooling system goes into overdrive and shuts down. This, along with too much salt lost through excessive sweating, can cause heat stroke. A patient with heat stroke usually has a body temperature above 39°C.

WHO IS AT RISK?

Actually, anyone who exerts themselves in excessively hot or humid conditions or who is overexposed to heat can suffer from heat stroke. However, young children and older folks are more susceptible, along with folks with chronic health conditions such as obesity, diabetes or heart failure – conditions which can all impede heat loss. Certain common medications can also interfere with the body’s thermostat and cooling, and include anti-depressants, antihistamines, gastrointestinal drugs, cardiovascular medications and diuretics.

ARE THERE TYPICAL SIGNS AND SYMPTOMS?

Yes there are, and they are generally easy to spot too. The person will have a very hot and dry skin that is red and flushed, but there is no sweating. Their skin may then turn pale or purple and feel clammy. This could be accompanied by a headache, muscle cramps in the arms, legs and abdomen, dilated pupils, hyperventilating or showing signs of confusion. Dizziness, nausea or stomach pains, a weak but rapid pulse rate and a drop in blood pressure are also symptoms of heat stroke, along with fever or cold shivers. There may even be temporary blindness. Rapid, shallow breathing, lethargy, convulsions and even loss of consciousness is possible in severe cases when body organs begin to fail. Sometimes, heat stroke comes on suddenly, other times it can take a few days to manifest.

HOW DO YOU TREAT IT?

Fast treatment for heat stroke is essential because the body temperature needs to be rapidly decreased to within normal limits – or organ damage, brain injury or even death may occur. Until emergency medical help arrives, ensure that the patient stops all physical activity immediately, move them to the coolest area available or create shade for them to lie under. Loosen or remove excess and synthetic clothing, but do not strip them naked. Lie the patient on their back with their feet elevated to direct blood flow back to the head, and fan them while pouring cool water over their body or covering them in wet towels especially on the head, neck, armpits, and groin. Move them into an air-conditioned room or use ice packs on their face and neck. If you can, immerse them in a bath of cool water but not very cold water. If water is too cold, it can drop the body temperature too low and cause hypothermia. 

To ease cramps, gently rub them and sponge them with warm water – and encourage the patient to stretch the muscles as much as possible. Give the person cool water to sip or a rehydration drink if it is available and they can swallow it safely. A teaspoon of sugar and a teaspoon of salt dissolved in a litre of water will also help as an interim measure if rehydration salts are not immediately available. Perform CPR if the patient stops breathing and do not give the patient any medication whatsoever.

WHEN DO YOU CALL THE DOCTOR?

Doctors will treat heat stroke according to its severity, after taking blood pressure and temperature readings to prevent hypothermia or the body temperature dropping too low. Blood and urine may also be taken to test salt and electrolyte levels so fluid therapy can be given to correct these imbalances.

If the patient is confused, agitated, has extreme fatigue, muscle aches, fever, nausea, convulsions or loses consciousness – call for medical help immediately as emergency treatment is needed.

WHAT CAN BE DONE TO PREVENT HEAT STROKE?

Actually there are plenty of common sense practices to avoid heat stroke. Most important is simply to avoid overheating and to stay well hydrated. Dehydration causes a heat stroke patient to deteriorate quickly and the condition becomes very serious.

If you are in a hot environment, keep drinking water and rehydration drinks – don’t wait to be thirsty first. Don’t exercise in extreme heat and keep meals light and without hot spices. Rest during the heat of the day and get out of the sun. Coffee and alcohol are diuretics and will further dehydrate you. If you are in a new hot environment, take time to acclimatize. Always wear a hat and sunscreen, light, loose cotton clothing and limit exposure to the sun. Use fans and air-conditioners to cool down and open windows for ventilation. 

Also, be aware of the reactions of any medications you are taking and whether they may impede the body’s heat control mechanisms. Most important is to recognise symptoms and know that the condition can become serious very quickly. Pay special attention if your hands and feet swell and you retain fluid in hot conditions, as this indicates the body is under stress.

As you look after yourself well in the heat, also remember to never ever leave any human or animal in a closed, parked vehicle. It exposes them to heat stroke and could very easily become fatal.