We all know we should put sun tan lotion on when we’re outside in the summer. Fewer of us understand exactly how sun tan lotion works. The sun emits radiation which damages the skin and increases your risk of skin cancer. These are called UVA and UVB rays. UVB rays cause sun burn and are carcinogenic, while UVA rays cause damage to the skin, increase signs of ageing, and also contribute to skin cancer. Sun cream works by blocking this radiation from being absorbed into your skin.
The higher the SPF rating, the more radiation is blocked by the sun cream. However, no sun cream will protect you completely. Most of us don’t use anywhere near enough sun cream when we put it on, so apply liberally. Make sure you reapply at least every two hours, as well as whenever you have got wet, sweated a lot or towelled yourself dry.