How often should sunscreens be applied for effective protection?

Effective protection from the sun's harmful ultraviolet (UV) rays requires that sunscreen be reapplied several times a day, especially if you are spending extended periods outdoors. The general guideline is to apply sunscreen at least every two hours and more frequently if you are sweating, swimming, or towel-drying. This is because the protective ingredients in sunscreen can wear off due to these activities, reducing its effectiveness.

By applying sunscreen multiple times throughout the day, you ensure a more consistent level of protection, which is essential for minimizing the risk of sunburn and long-term skin damage. This frequent application is particularly important at higher altitudes or during peak UV radiation hours when the risk of skin damage is significantly increased.

Other options imply insufficient frequency of application. For example, applying sunscreen only once a day or only after swimming does not account for the cumulative effects of UV exposure throughout the day. Moreover, using sunscreen a few times a week fails to provide ongoing protection on days spent outdoors. Therefore, consistently reapplying sunscreen several times a day is crucial for comprehensive sun protection.