A serious heat wave hit several European countries, including Belgium, in mid-July. Many of us seek to cool off and endure the suffocating heat as much as possible. Be careful however, certain gestures, which may seem instinctive, are sometimes counterproductive. Small summary of false good ideas.
During the heat, the nights can sometimes be as complicated as the days, sleep being particularly difficult to find when the temperature is too high. To cool off and hope to fall into the arms of Morpheus, it can be tempting to sleep naked. A practice that brings benefits in normal times (such as better temperature regulation) but which is not indicated in the event of a heat wave. “ Sweat builds up on the body and stays there ,” explains Dr. Julius Patrick, chief sleep physiologist at Bpu’s Cromwell Hospital in London, to the British edition of Cosmopolitan magazine .
He is joined by Dr Neil Stanley, from the UK’s Sleep Station program, in the columns of the Daily Mail Plus: ” To bring down the temperature, sweat must be wicked away from your skin. If moisture remains on your skin (because it is not absorbed by clothing, it prevents the body to dissipate heat “.
It would therefore be more appropriate to wear clothes – light ones of course – to sleep in hot weather. In this regard, natural fibers, such as cotton or silk, will be more effective at wicking away sweat than synthetic materials. ” Between cotton and nudity, choose cotton. But if you have to choose between synthetic fibers and nudity, choose nudity “, sums up doctor Julius Patrick. Who also recommends not necessarily storing the blankets in the closet. In the same logic, fine cotton sheets also absorb sweat.
Take a cold shower
What could be more normal than wanting to take a cold, even freezing, shower when temperatures exceed 30 degrees? And yet, it is clearly to be avoided. A cold shower may, in fact, make you even hotter. And for good reason, man is “a homeothermic animal”, as explained by Brigitte Tregouet, general practitioner to our colleagues from the Huffington Post . We naturally regulate our internal temperature so that it stays around 37.5°. ” When it’s cold, (the body) produces heat internally and externally ,” explains the GP. With a cold shower, the body will therefore have to compensate to regulate itself, which will result in the production of heat.
Especially since intense and rapid thermal contrasts can be downright dangerous for certain categories of more fragile people. Conversely, prefer a shower at normal temperature, even 4 to 5 degrees less than the ambient temperature. Leaving, ” the water evaporates, causes cold, it refreshes and lowers the body temperature “, continues the doctor. As our colleagues point out , the principle is the same with the use of a fogger, which is particularly effective for cooling off.
Bathe in the first water point you come across
With the high temperatures expected in the coming days, many people will rush to water points, swimming pools, the sea, and other lakes to mitigate the suffocating effect of high temperatures. Swimming yes, but not just anywhere. Doctors insist on the importance of choosing authorized bathing places. At the risk of having bad surprises.
As Jean-François Toussaint, director of the Institute for Biomedical Research and Sport Epidemiology (Irmes), reminds us, interviewed by our colleagues from RTL France , outdoor water points can be polluted. “ We risk a lot of things. It all depends on what the water is polluted with, whether it is chemical toxins, whether it is bacteriological toxins“, challenges the doctor. “Rat droppings cause leptospirosis”, warns Axel Lamotte, member of the steering committee of the French Federation of Lifeguards, questioned by the Dispatch. “There can also be staphylococci, which can be very dangerous”. Especially since the heat ” multiplies pathogenic germs in all waters “.
Drink ice water
The logic is the same as that of the cold shower. Here too, the practice brings instant coolness, but the body must then compensate, and produce heat, to stay at 37.5°. Opt for room-temperature drinks instead. Preferably mineral water. This allows, according to Françoise Grammont, dietician nutritionist, questioned by our colleagues from Marianne , to ” decompensate the loss of minerals in perspiration “.
In the same way, some go so far as to advise against the consumption of frozen foods. ” If you eat ice cream, for example, this food will take the place of another more thirst-quenching food like water, so you won’t be able to cover your water needs for the day “, explains Françoise Grammont, dietician nutritionist, interviewed by the French magazine. Same observation on the side of Ameli, the French social security site , which insists: ” This quickly reduces the feeling of thirst and you risk not hydrating yourself enough to cover your needs “.
Drink too much
This is not new: in case of hot weather, it is particularly important to (well) hydrate. Between 1.5 and 3 liters per day, more than usual to compensate for the increased perspiration induced by the heat. Be careful, however, when it is particularly hot, you may be tempted to drink a lot, even too much. When the quantities ingested are really too large, the body can go into a state of overhydration, hyponatremia, the consequences of which can be very serious (even cerebral edema). This point is, however, also valid outside of heat waves.
Air conditioning and excess fan
Using a fan or air conditioning is obviously recommended in the event of a heat wave. But be careful not to abuse it. During the night, some tend to want to leave the fan running to cool off and find sleep. An “average option” in the eyes of Jean-François Toussaint, unless it is ” directed towards the lower body and not directly on the lungs “. At the microphone of RTL , the doctor also advises to hydrate all the better during the day, ” so as not to suffer from dehydration because of the draft created by the fan “.
As for air conditioning, too great a difference between the indoor and outdoor temperature can have harmful consequences on the mucous membranes. But also promote the possibility of contracting a virus.