What is it about ?
A number of problematic situations can suddenly occur when the ambient temperature is very high. We think of dehydration, heat swelling (heat edema), heat cramps, heat exhaustion, sunstroke or even heat stroke. The heat can therefore be dangerous for health. Heat stroke can even be fatal. Especially when the humidity level in the air is high, the body temperature can rise rapidly even if the ambient temperature is not very high.
Where do we meet them?
Anyone can suffer from heat, but some groups need to be extra careful, as they are more sensitive than others to heat and sun:
- children,
- people over 65 (in good health),
- people with a chronic condition such as asthma, cardiovascular disease, diabetes or kidney disease,
- athletes or people who must make great efforts in hot weather,
- people who are in poor physical condition and / or who are considerably overweight,
- people who drink too much alcohol,
- people taking certain medications (eg antidepressants or water pills).
How to recognize them?
Sweating a lot and not drinking enough can lead to dehydration. When you’re dehydrated, you get very thirsty, have a dry mouth, and headaches.
Heat edema manifests itself in the lower limbs. It mainly affects people who are obese and / or have high blood pressure (hypertension).
Sunstroke is caused by exposing the (bare) head to a direct source of heat, causing severe headache, nausea and dizziness. You may also have other symptoms indicating over stimulation of the central nervous system, such as drowsiness, fainting (syncope), and fever.
Heat cramps appear especially when you sweat excessively while making intense physical efforts. These are most often muscle cramps, usually in the calves, which go away with rest.
Heat exhaustion occurs after a period of heat in which the body becomes dehydrated. It can be the first sign of heatstroke. The main features are dizziness, weakness, fatigue, insomnia or unusual nighttime restlessness.
Heat stroke is usually the result of prolonged exposure to high temperatures. It can lead to serious complications. Heat stroke can be recognized by high body temperature (over 39 ° C and up to 45 ° C), increased heart rate (over 100 beats per minute), unusual restlessness, hot, red and red skin. dryness, headache, nausea and vomiting, seizures, unconsciousness or even coma. This is a medical emergency which, if left untreated, can lead to death in a short time.
How is the diagnosis made?
The doctor will examine you and look for signs of hyperthermia. If he suspects heat exhaustion or heat stroke, he will also be alert to the possibility of an epileptic fit, brain hemorrhage, simple fainting (when you just fizzle out) , your body temperature is normal) or a serious infection. A rapid blood glucose test (blood sugar level) with a drop of blood drawn from the fingertip and a blood test will allow him to rule out these possibilities.
In case of suspected central nervous system infection or cerebral hemorrhage, a lumbar puncture may sometimes be performed.
What can you do ?
When announcing hot weather, follow the tips below to prevent heat-related illness:
- Avoid strenuous physical exertion outside between 11 am and 10 pm;
- Limit your physical efforts or take regular breaks;
- Drink enough: at least 1.5 to 2 liters at rest (water, energy drink, cooled broth) and do not wait until you are thirsty to drink;
- Avoid alcoholic and caffeinated drinks, as they disrupt your body’s natural water balance;
- Stay indoors in a cool place. Cool your body regularly (shower, bath, swimming pool, …);
- Wear light clothing and protect your head from the sun (hat or cap);
- Also protect your skin from the sun, by applying a good sunscreen (with the appropriate protection factor);
- Pay close attention to the elderly and children;
- Ask the doctor if the medications you are taking can negatively impact your health during a heat wave. Sometimes the dose will need to be adjusted.
If a person loses consciousness and there is a risk of heatstroke, the first thing to do is to cool him down (after resuscitation or put in a lateral safety position by a competent person). The best method is to pour water all over the skin while exposing it to a blower to cool it. It is strongly recommended not to use ice or a cold-pack, or to immerse the body in water.
To relieve heat edema, you can rest with your legs elevated and drink enough. Check with the doctor to determine if your medication may need to be adjusted.
To avoid heat cramps, energy drinks can be useful (certainly during prolonged efforts). They contain long chains of carbohydrates and 0.1% salt water (or half a teaspoon of salt in 2 liters of water). Avoid drinking only water when exercising, as water disrupts your body’s water balance.
Heat exhaustion can be avoided by staying hydrated (drinking fluids). This will prevent you from becoming dehydrated.
What can the doctor do?
Heatstroke
Heat stroke is the most serious heat illness. It is potentially fatal. If so, the doctor will give you first aid (to save your life) and cool you down as quickly as possible. He will give you oxygen and rehydrate you (by infusion). The rest of the treatment for heat stroke takes place in the hospital.
In addition, your doctor will also take a blood test to rule out other possibilities and assess the balance of electrolytes in your blood (potassium, sodium). If this balance is disturbed, it must be corrected. The kidneys are closely monitored because heat stroke can decrease their function (acute kidney failure).
After heat stroke, the EKG (recording of heart activity) sometimes reveals abnormalities that can look like a heart attack.
Heat exhaustion
If your body is showing signs of exhaustion, you need to hydrate yourself. The doctor will decide, on the basis of a measurement of the electrolytes in the blood, the best treatment to be given on a case-by-case basis.
Hypertonic dehydration (usually caused by a combination of physical exertion and heat) occurs when fluid losses are not compensated for. The correct remedy is to drink water.
Hypotonic dehydration is dehydration that is accompanied by a lack of salt. It occurs when you drink only water to hydrate yourself. In this case, you suffer from headaches, weakness, nausea, and upset stomach and intestines. You are often less thirsty if you have hypotonic dehydration than if you have hypertonic dehydration. The doctor will give you a saline solution by infusion.
Isotonic dehydration, for example, occurs in heat-exhausted elderly people. In this case, the doctor will carefully check the composition of the blood and blood circulation, then give salts and sugar by infusion.
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