Dermatologists identify common sunscreen mistakes that increase skin cancer risk

Dermatologists have warned that many people are using sunscreen incorrectly, leaving their skin vulnerable to cancer.

Common errors include applying too little product, rubbing it in too hard, and failing to reapply it during the day. Rubbing sunscreen vigorously can push it into skin creases and cut its effectiveness by around 25 percent. Only one in three Americans reapplies sunscreen every two hours, as doctors advise. Even fewer, just 20 percent, wear it on cloudy days, even though UV rays still reach the skin through cloud cover.

Experts recommend a broad-spectrum product with SPF 30 or higher, applied 15 to 30 minutes before going outside. Using SPF 15 sunscreen daily has been shown to lower the risk of melanoma by 50 percent. Sunscreen kept in hot cars loses its effectiveness before the expiry date printed on the bottle.