HOT CLIMATE AND HEAT STROKE
Heat stroke is a medical emergency. It is a serious form of heat injury. If there is suspicion of heat stroke please call for an ambulance. While waiting for the ambulance please start First Aid.
Heat stroke can kill/ damage brain cells and other internal organs particularly in the age group above 65 and children below 4 years. Athletes are also vulnerable to the effects of excessive heat.
Heat stroke often occurs as a progression from milder heat related illnesses such as heat cramps, syncope (fainting) due to heat, and heat exhaustion. However it can also occur even if there are no previous signs of heat injury.
How does heat stroke occur and why?
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 40.50C, with complications involving the central nervous system”. This occurs after exposure to high temperatures.
Symptoms of heat stroke:
Hallmark of heat stroke is a core body temperature above 40.50C.
Fainting may be a first sign.
Dizziness and light headedness.
Lack of sweating despite the heat.
Red, hot and dry skin.
Muscle weakness.Nausea and vomiting.
Rapid heartbeat which maybe strong or weak.
Rapid shallow breathing.
Behavioural changes such as confusion, disorientation or staggering gait.
First aid for heat stroke:
If there is suspicion of heat stroke please immediately call for an ambulance or transport the person to a Hospital. Any delay could be fatal!! While waiting for the ambulance and paramedics to arrive, initiate first aid.
Move the person to an air-conditioned environment or at least a cool, shady area and remove any jackets /coats or any warm clothes.
If possible, take the persons temperature. If hot, initiate first aid to cool the body to 380C. If there are no thermometers, start first aid anyway.
Fan air over the patient while wetting his or her skin with water from a sponge or hose.
Apply ice packs to the patient’s armpits, groin, neck and back. These areas are rich with blood vessels close to the skin so cooling these areas may reduce body temperature faster.
If possible, immerse the patient in a shower or tub of cool water or an ice bath.
If emergency response is delayed, call the hospital emergency for additional instructions.
Risk factors for heat stroke:
Heat stroke is most likely to affect older people who live in apartment or homes lacking air conditioning or good airflow.
Other high risk groups include people of any age who don’t drink enough water, have chronic diseases or who drink excessive alcohol.
Heat stroke is strongly related to the heat index (measurement of how hot you feel when the effects of relative humidity and air temperature are combined). A relative humidity of 60% or more hampers sweat evaporation which prevents your body’s ability to cool itself.
If you live in a town area, you may be especially prone to develop heat stroke during a prolonged heat wave, particularly if there are stagnant atmospheric conditions (no breeze/ no wind) and poor air quality (high API). This is known as the “heat island effect” (tar and concrete store heat during the day and only gradually release it at night resulting in higher temperatures at night).
Infants and children up to 4 years of age and adults above 65 years are particularly vulnerable because they adjust to heat more slowly as compared to other age groups.
People with health conditions such as heart, lung or kidney diseases as well as those who are obese or underweight, hypertensives and diabetics are more vulnerable as well. People suffering from mental illnesses, sickle cell trait, alcoholism, sunburn as well as any condition that can cause fever are also at risk.
Medications such as; Antihistamines (cold and allergy pills), diet pills, diuretics, sedatives, tranquilizers, stimulants, anticonvulsants, heart and blood pressure medications (beta blockers and vasoconstrictors), medications for psychiatric illnesses (antidepressants and antipsychotics).
Preventing heat stroke:
When the heat index is high, it is best to stay in an air-conditioned environment.
Wear lightweight, light coloured, loose fitting clothing. If possible wear a hat.
Use a sunscreen (SPF 30 or more).
Drink extra fluids. To prevent dehydration, it is generally recommended to drink at least 8 glasses of water/ fruit juice or vegetable juice per day. Because heat related illnesses also can cause salt depletion, it is also advisable to take an electrolyte rich sports drink (e.g. 100 plus, isotonic drinks) as a substitute for water during periods of extreme heat and humidity.
Take additional precautions when exercising or working outdoors. The general recommendation is to drink 3 cups of fluid 2 hours before exercise, and take 1 cup of water or a sports drink right before exercise. During exercise you should consume a cup of water every 20 minutes even if you don’t feel thirsty.
Reschedule or cancel outdoor activities. If possible, shift your time outdoors to the coolest times of the day (early morning or after sunset).
Monitor the colour of your urine. Darker urine is a sign of dehydration. Be sure to drink enough fluids to maintain very light colour urine.
Measure your weight before and after physical activity. Monitoring lost water weight can help determine how much fluid you need to drink.
Avoid fluids containing caffeine or alcohol. Both these substances can make you lose more fluids and worsen heat related illnesses.
Do not take salt tablets without consulting your Doctor. It is best to take sports beverages like 100 plus etc. or fruit juices to replace lost electrolytes.
If you have epilepsy, heart disease, kidney disease or liver disease or if you have a problem with fluid retention; where you have to maintain fluid restriction, please consult your doctor before increasing fluid intake.
If you live in an apartment or house without fans or air conditioning, try to spend at least 2 hours each day preferably during the hottest part of the day in an air conditioned environment.
At home draw your curtains, shades or blinds during the hottest part of the day. Open your windows at night on both sides of your building to create cross ventilation.
Post recovery from heat stroke:
After you have recovered from heat stroke, you will be more sensitive to high temperatures during the following week. It will be best to avoid hot weather and heavy exercise till your doctor tells you it is safe to resume normal activities.
Universiti Putra Malaysia
Selangor Darul Ehsan