8 Ways to stay protected

You squeeze it out, slather it on, call it a day. Yeah, no. Sunscreen can only do its job – shield skin from damage – if you do yours. And that involves some education (and, yes, reapplication).

1 Use more “People who apply SPF30 usually get the efficacy of a 10 or 15,” says dermatologist and surgeon Dr Steven Q Wang. “Most apply one milligram per square centimetre instead of two.” The solution isn’t to buy SPF100 and keep skimping, but to apply several thin layers of broad-spectrum sunscreen.„

2 Reapply Apply sunscreen at 8am, and you’re not covered for a 10.30 coffee run, much less alfresco lunch, as most sunscreens work for about two hours. If you’re inside for most of the day, touch up before you go outside.„

3 Rethink protection “Sun-protective clothes are much easier; you don’t have to worry about reapplying or sweating it off,” says professor of dermatology Dr Kristin Nord. Add a hat with a brim at least 8cm wide. One caveat: a hat won’t protect against rays that reflect off the sand.

4 Replace your shades

A new study suggests sunglasses with broad-spectrum protection may be less effective with time. Replace yours every couple of years and use a case to prevent scratches that let UVA rays through, says Dr Michael Ehrlich, an assistant professor in ophthalmology. (Sunscreen expires in about a year.)

5 Be consistent “The eyebrows and hairline are where I typically see melanoma,” says dermatology assistant professor Dr Francesca Fusco. She suggests using clear sunscreen on brows and blending with a spooley brush. Spritz a spray sunscreen on a makeup wedge and pat over your hair parting.„ 6 Read the ingredients Four ingredients protect against UVA1 rays, which cause ageing and mutations that can lead to cancer. The most effective is avobenzone, says Dr Nord, but it’s not stable in sunlight unless paired with an ingredient called octocrylene. For a physical block, zinc oxide is your best broad-spectrum bet.„

7 Apply SPF every day Even five minutes without sunscreen is damaging as the sun triggers a reaction that damages DNA in unprotected skin cells – a reaction that continues for up to four hours (long after you’re back inside). Altered DNA can lead to skin cancer. But your skin has a chance to repair itself if you’re vigilant about protection. Even for errands. Even when it’s cloudy.

8 Don’t rely on umbrellas New research suggests shade alone can’t save you from sun damage. After three and a half hours, 78% of study participants sitting under an umbrella without wearing sunscreen had sunburn. Shade or sunshine, apply sunscreen 30 minutes before you head outside. It needs time to penetrate and saturate the skin, explains Dr Fusco.