Reapply sunscreen every two hours – immediately after water and sweat

Paris – 02.08.2026: Sunscreen should be reapplied approximately every two hours during extended periods outdoors. However, this widely used guideline is no guarantee that the protective layer will remain fully intact for that long. As Franceinfo explains, citing French health recommendations, actual protection also depends on whether the skin comes into contact with water, sweats heavily or is dried off.

After swimming, sunscreen must therefore be reapplied immediately. This also applies to products labelled water-resistant. French health insurance provider Assurance Maladie points out that such a label does not promise unchanged protection for an entire day of swimming. Water, movement and extended periods outdoors can affect the applied layer.

The same applies during sports, physical work or heavy sweating. Rubbing the skin with a towel also removes part of the product. Anyone who continues to be exposed to the sun afterwards should carefully reapply sunscreen to uncovered areas and should not wait until two hours have passed since the last application.

According to Assurance Maladie, the first application should be made around 30 minutes before going out into the sun. The product must be applied generously and evenly. In practice, too little is often used, meaning that the stated sun protection factor is not achieved. Ears, temples, the neck, the backs of the hands and the tops of the feet are easily forgotten. The chosen product should protect against both UVB and UVA radiation.

A high sun protection factor does not extend indefinitely the amount of time a person can spend in the sun without risk. The health insurance provider recommends at least SPF 30. For children, UVA and UVB protection with SPF 50 is preferred. Babies and toddlers should, if possible, not be exposed to direct sunlight at all.

Sunscreen is also only one part of prevention. The French National Cancer Institute additionally recommends tightly woven clothing, a hat, suitable sunglasses and regular time spent in the shade. Direct summer sunlight should be avoided where possible between 12 p.m. and 4 p.m., as ultraviolet radiation can be particularly intense during this time. Protective measures are also advisable when the sky is cloudy, as UV radiation partly penetrates clouds.

Particular caution is required for children and for people with very fair or sensitive skin. Redness, pain or a feeling of heat may indicate sunburn. Those affected should leave the sun immediately and protect their skin from further radiation. In cases of extensive, severe or blistering burns, Assurance Maladie advises seeking medical assessment.