What are the dangers of the heat wave? Who are the most vulnerable people and how to control their hydration during hot weather ?

During a heat wave, we are subjected to high temperatures that put our bodies to the test. Indeed, to avoid a rise in body temperature, the body has different means, the main one being perspiration. In this article, we will see what the heat wave is as well as its dangers and risks. Then, we will see the most vulnerable people during heat waves as well as the means allowing to control its level of hydration.

What is the heat wave?

A heat wave is a period of very hot weather day and night for at least 3 consecutive days. Heat waves usually occur in the summer, most often between July 15 and August 15. We speak of a heat wave when the temperature does not drop below 18-20°C at night and when it is above 30-35°C during the day.

What are the dangers and risks of the heat wave?

During a heat wave, heatstroke can occur. Indeed, heat stroke appears following prolonged exposure to high heat. It is manifested by fever (or hyperthermia) up to 40°C, a feeling of intense thirst, dizziness, drowsiness, nausea and/or vomiting or even blurred vision.

Dehydration is a lack of water and mineral salts in our body and essential to its proper functioning. Thus dehydration can occur during heat waves or high temperatures. To know if your body is in a state of dehydration, it is necessary to recognize its symptoms which are:

• a thirst,

• dry lips,

• weight loss,

• abnormal fatigue or loss of strength.

In case of severe dehydration , we observe:

• a dry mouth, tongue and skin,

• fever,

• concentrated urine and in small quantities.

If the symptoms persist or if you show signs of severe dehydration, this can have harmful consequences for the body, so call your doctor or 15 (SAMU).

The heat is especially painful:

• when the body has not yet adapted (at the beginning of the heat wave),

• when it is damp (sweat does not evaporate) and there is no wind (water vapor remains "stuck" to the skin),

• when atmospheric pollution adds its effects to those of heat.

Extreme heat can have other consequences such as an aggravation of existing pathologies, unusual fatigue or even digestive disorders such as diarrhoea.

Medication, heat wave and dehydration?

Certain medications can play a role in the effects of the heat wave on the body. Among the latter, we can find aspirin which modifies renal functioning. There are also diuretics which can increase the risk of onset of dehydration because they allow a greater elimination of water by the kidneys or even certain antimigraine and neuroleptics.

However, despite an increased risk of appearance of the effects of the heat wave, you should not stop your treatments yourself, this must be seen with your doctor and your pharmacist.

The most vulnerable people during a heat wave ?

Children, pregnant women, seniors and athletes are the most vulnerable during a heat wave.

Indeed, the elderly, that is to say over 65, sweat little, which makes it difficult to maintain a body temperature at 37°C. As a result, too high a rise in this temperature can cause heat stroke.

As for children under 4 years old and infants, they sweat more in order to lower their body temperature. This perspiration leads to the loss of water and mineral salts which can lead to dehydration.

Finally, when practicing a sports activity, there is an increase in body temperature, potentiating sweating and this can lead to a state of dehydration.

How to control your hydration during these high temperatures?

There are different ways to control your hydration during heat waves. First, avoid the heat which is the main cause of dehydration. Thus, to fight against the heat, it is preferable to wear light and loose clothing that allows the evaporation of perspiration and limits physical effort. You should also try to stay in a cool place by ventilating only at night or by using a fogger or air conditioner, while avoiding going out during the hottest hours of the day, between 12 p.m. and 4 p.m.

It is also essential to help our body cool down by taking a cool shower or wetting the face and neck, as this helps reduce perspiration.

The control of its level of hydration is also done through food. Indeed, it is necessary to favor cold dishes as well as fruits and vegetables that are rich in water such as watermelon, tomato, celery or cucumber. Remember to eat enough (neither too much nor too little).

To maintain a good level of hydration, it is essential to drink sufficient quantities of water to compensate for losses. And avoid drinking alcohol (which dehydrates).

In case of significant losses, it is also necessary to compose the mineral salts at the risk of having deficiencies.

Limit your physical activity as much as possible:

• Prohibit any effort (sport, gardening, DIY),

• Postpone what is urgent in cool hours,

• If you have to do an activity, wet your T-shirt and cap before putting them on, let them dry on your skin and repeat the process.

Hydratis pellets allow you to control your hydration while preventing dehydration. Indeed, these pellets are composed of magnesium, potassium, chloride, manganese, zinc, or even salt which allows better absorption of water by the body while providing mineral salts. There is also a special senior range in the form of sachets.

In conclusion, the heat wave leads to significant water loss through perspiration which must be compensated for in order to avoid dehydration. To reduce losses, you must minimize the rise in body temperature by trying to keep your habitat as cool as possible or by eating cold meals, for example. In addition, it is essential to hydrate well without waiting for the feeling of thirst which is already a sign of dehydration, avoid alcohol and sport.