By Dr Fiona de Ferrars, Okement Surgery (part of the Wallingbrook health group) based in Okehampton Community Hospital SUNNY weather is here and so now is the time to plan ahead to avoid suffering the pain of sunburn. Sunburn is caused by the skin being damaged by ultraviolet light, which is usually from the sun or tanning beds. Sunburn starts five hours after sun exposure and makes the skin red, tender or even blistered for a few days and then gets better. However, every time that you get sunburnt you are doing permanent damage to the skin and so increasing the chance of developing skin cancer and moles as you get older. The risk of skin cancer is increased if you were burnt badly enough to have blisters when you were a child. Sun exposure also causes wrinkles by affecting the elasticity of the skin. The best way to keep skin beautiful and healthy is by preventing sunburn. Try to stay in the shade between 11am and 3pm. If you go in the sun, cover up with clothing and wide brimmed hats. Remember that the sun's rays can penetrate light clothing. Apply plenty of sunscreen with a sun protection factor (SPF) 30 to any exposed skin, ideally half an hour before going in the sun, and then every two hours. Waterproof sunscreen lasts longer but can still be washed or sweated off, so make sure that you put on more after going in water. Most people do not apply sunscreen thickly enough, and this reduces the SPF. It is common practice for SPF 15 sun cream to be applied so thinly that it is equivalent to only SPF 3. It is necessary to use two large, cupped palmfuls of sunscreen to cover an adult wearing only a bathing suit. Sunscreen has a shelf life of 2-3 years. Choose a broad spectrum sunscreen which protects against UVA (ultraviolet A rays) and UVB (ultraviolet B rays) , as they both cause long term damage to the skin. The SPF measures the amount of protection against UVB. The amount of protection against UVA is shown by stars on the bottle, with more stars showing better protection. Sunscreen never gives 100% protection and although it helps to prevent sunburn, there is no evidence that it prevents skin cancer. Some people are allergic to sunscreen, but fortunately there is a wide range of substances used in different sunscreens. The chemical sunscreens make the UV light more harmless but sometimes sting or cause dermatitis, whereas the physical sunscreens are opaque, gentler and work by blocking the sun's rays. There are many things which increase the risk of becoming sunburnt. I think that everyone knows that fair skinned people are more likely to become sunburnt than people with darker skin, and that the UV rays from the sun cause a dark pigment called melanin to be formed in the skin, which helps protect the skin. However, having a suntan is a sign of the skin having been damaged, and the longer you stay in the sun, then the more damage is done. The height of the sun is also important, as the nearer you are to the sun, the more likely you are to get burnt. So be especially careful at mid-day, mid-summer and near the Equator. Mountaineers have to be careful as the sun's rays are stronger the higher they climb. This is not due to closer proximity to the sun, but rather to there being less atmospheric filtration. People in the South West can be at high risk of sunburn if, as soon as the sun shines, they strip off their clothes and dive into the dazzling sea. The power of the sun's rays is magnified not only by the reflection of the sand and the sea, but also by the water on the skin. The cool water prevents people from realising that they are burning. The best treatment for sunburn is to apply a cold moisturising cream, or a cold flannel. Moisturisers which contain aloe vera are very soothing, and calamine lotion can help relieve itching. It is important to keep a balanced view on sun exposure and to remember that everyone needs to have some sunshine in order to produce vitamin D. Vitamin D is essential to maintain strong bones. Research has shown that some children, especially in the north, are being over-protected from the sun, so that they are developing weak bones, which is called 'rickets'. It is sensible for people with dark skin or people who don't go outside to take vitamin D tablets over the winter, especially if their legs start to ache. Please see your own GP if you have any questions.