The first heat waves are occurring earlier and earlier in France, as demonstrated by the heat waves of 2025 and 2026, which began as early as May. Many regions were placed under an orange or red alert due to very high temperatures lasting several consecutive days. Santé publique France is actively monitoring the heat waves to assess summer risks and implement appropriate preventive measures. The agency reminds the public that extreme heat affects health and hasan immediate impact on the body, regardless of age. In addition to its direct effects, exposure to heat causes unusual fatigue, leading to a loss of alertness and reflexes, which can result in accidents of all kinds; it is therefore essential to protect oneself by adjusting one’s activities and hydration.

Furthermore, these early heat waves occur during specific periods: exam season for students, cultural events (Music Festival), and sporting events, among others. Heat wave prevention measures therefore apply to everyone. 

These rising temperatures encourage swimming and water activities, increasing the risk of accidental drowning and the number of drowning deaths. Simple precautions ensure safe swimming: actively and constantly supervise young children, follow safety guidelines, and be mindful of your physical condition.

What are some good habits everyone should adopt during heat waves?

• Drink water regularly, before you get thirsty
• Stay cool at home or in a cool place near your home (library, movie theater, stores, swimming pool, air-conditioned room, etc.) and avoid going out until late in the day
• Opt for light activities
• Eat light, balanced meals
• Limit coffee or tea and avoid alcohol: these drinks contribute to dehydration

If you are in a high-risk group (seniors, people with disabilities), consider registering with your local municipality to receive assistance during periods of extreme summer heat.

In the home

During the day, blinds, shutters, curtains, and windows should be:

• Kept closed on the side facing the sun, unless the home benefits from shade provided by a tree or external sun protection (awning, pergola, gazebo, umbrella, etc.). Limiting the sun’s impact on glass surfaces slows down the entry of heat into the room;
• Opened on the shaded side if this allows for cross-ventilation. In this case, hang a damp towel so that evaporation cools the air. If it is not possible to create a draft using only the windows on the shaded side, keep them closed.

As soon as outdoor temperatures are lower than indoor temperatures: open blinds, shutters, and windows wide to let in cool air and refresh your home.

Find more tips and advice on how to adapt your home or your physical activities when it’s hot—not just during heat waves—on the website: vivre-avec-la-chaleur.fr.

When traveling by car

• Travel during the coolest hours of the day
• Be sure to bring enough water for every trip
• Never leave anyone—especially a child—alone in a car, even for a short time

Specific advice for workers and employers

In addition to the direct effects of heat, fatigue caused by both heat and work can lead to reduced alertness and workplace accidents. To limit weather-related workplace accidents, employers are required to implement a few simple measures mandated by regulations (providing workers with a rest area suitable for the weather conditions, organizing the worksite to allow for breaks under equivalent safety conditions, etc.). The INRS provides resources to help employers take action and raise employee awareness.

• Learn more: www.inrs.fr/chaleur (information packet on working in extreme summer heat)

Tools and Information Resources for Healthcare Professionals

• The vivre-avec-la-chaleur.fr website: practical advice for adapting to daily life
• Communication tools and materials (posters, brochures) for professionals and local authorities, available for download and by order
• Météo-France.fr: weather advisory map providing real-time updates on weather conditions