Early summer heat: recommendations to follow
When the sudden arrival of summer takes the form of a heat wave, it can be difficult for the body to adapt. What are the high-risk situations and who are the persons most at risk? What preventive measures should we take, how can we detect the warning signs and how should we respond if they appear?
When does heat become a hazard?
“Heat waves”, due to their intensity and duration, create one of the most high-risk situations. They are characterised by “extreme” daytime and night-time temperatures lasting at least three consecutive days. While the duration of a heat wave is clearly stated from the moment it is announced, the actual temperature threshold varies according to location and biometeorological indicators. Météo France would consider the Rhône to be under a heat wave when temperatures climb above 34 °C in the daytime and 20°C at night, whereas in Calvados temperatures upwards of 31°C in the daytime and 18°C at night would be considered heatwave conditions.
A “heatwave” therefore requires a high threshold of alertness but clearly precautions must be taken before this stage is reached. Heat starts to become a hazard in the following situations:
- high humidity with very little wind
- during the first waves of heat, even if they only last for a day or less, since the body has not been used to this for several months
- when temperatures recorded during the daytime do not fall or hardly fall at night, so that our bodies are not given time to recover
- atmospheric pollution which contributes to increased temperature
Who are the persons most at risk?
Depending on age and lifestyle, the body responds to heat in different ways. Below are the populations least likely to have a good tolerance of elevated temperatures:
- the elderly. After a certain age, the body no longer perspires as much and has difficulty maintaining its temperature at 37°C. If body temperature increases and exceeds 40°C, this is referred to as hyperthermia. This is equivalent to a heat stroke, which can among other things cause impaired consciousness.
- all of the other populations perspire a great deal to maintain the right body temperature, and this can lead to dehydration. Toddlers are particularly at risk. They are also not necessarily aware of their hydration requirements.
- for persons working outdoors and performing physical tasks, the risk is high. They perspire profusely to keep their body at the right temperature.
How can you protect yourself from the heat?
It is advisable to adopt good habits, especially if you are a high-risk person. However, the following tips can be applied by everyone:
- hydrate on a regular basis. This may seem obvious, but there is a risk of failing to drink enough liquid since the body is not necessarily timely in informing us of its hydration requirements. Water is preferable to fizzy drinks and alcohol should naturally be avoided, as it would make the situation worse.
- keep your body cool by wearing loose clothing
- use water misters and fans
- ventilate the room as much as possible at night and close blinds during the day
- opt for a diet of fruits, vegetables and cold dishes
- limit physical activity as much as possible, especially if performed in the sun
What are the warning signs and how to respond
Despite the precautions taken, intense heat can lead to health consequences. Here are the signs that should serve as warnings to you and those close to you:
- intense fatigue and insomnia
- incoherent speech
- dehydrated skin and mucous membranes
- loss of consciousness
- less frequent urination and darker-coloured urine
- accelerated breathing and heart rate
Depending on the intensity and severity of the symptoms mentioned above, the following set of appropriate measures should be taken:
- take liquid immediately, even if you are not thirsty
- increase ventilation and keep skin moist
- discontinue all physical activity
- stay in a cool place
- if symptoms persist or worsen, call the doctor or the emergency services
- while waiting for the emergency services, place the person in a cool place, hydrate the person if s/he is still conscious, remove clothing and place ice bags on thighs and arms.