A small dab, like you’d use for a day cream, usually isn’t enough. Two generous lines of sunscreen along your index and middle fingers are a rough everyday guide for the face. This isn’t an exact measure: finger length, tube opening and face size all vary. Your neck, ears and other exposed areas need extra. Spread it evenly and follow the amount recommended on your product.

Outdoors, choose at least SPF 30 with UVA and UVB protection. Apply it before you go out, and reapply about every two hours outdoors, as well as after swimming, heavy sweating or towel-drying. For swimming and sports, you need a water-resistant product – and you still need to reapply. Shade and clothing are part of sun protection too.

One example for everyday use is the SKIN1004 Hyalu-Cica Water-Fit Sun Serum SPF50+. With any product, the key is to apply enough of it. Reapplying keeps up your protection, but it doesn’t extend how long you can safely stay in the sun.