We all know that a little bit of sun is good for you, but as with everything, too much can be detrimental. Without protection, the suns UV rays will damage your skin, leading to sun burn and potentially skin cancer. But before you choose a sunscreen you need to first understand what the rating means. Most sunscreens nowadays contain broad spectrum UV filters that protect the skin from both UVA and UVB rays, and so a generic SPF rating is used. This is a measure of the fraction of UV rays reaching the skin. So for a SPF15 sunscreen, only 1/15th of the sun rays will reach the skin. You now need to roughly know how long it takes your skin to burn without any sunscreen to work out the protection time. If your skin burns in twenty minutes, then an SPF15 will give you 15 x 20 minutes in the sun = 300 minutes before burning. Obviously the higher the SPF, the longer you are protected in the sun. However, high SPF sunscreens do not last or remain effective on the skin any longer than lower SPF sunscreens and so must be continually reapplied as directed. The same is true with waterproof sunscreens. They will stay on the skin if you go in the water, but if you dry yourself with a towel or perspire, then you will need to reapply.If you should get sun burnt or your skin has dried in the sun and surf, then moisturisers and after sun cream and lotions are ideal for re-hydrating skin and reducing inflammation and tenderness. The other issue with staying out in the sun unprotected is the potential to contract heat stroke. Being upright animals, the tops of our heads receive the most sun. Wearing a sun hat during the hottest part of the day will provide shade to your crown and also help protect extremities that are difficult to fully apply sun cream to, such as tops of ears and your scalp. The last part of the body to protect from the sun , and ones that are often overlooked, are the eyes. Long term exposure to UV radiation can damage the internal mechanisms, potentially leading to cataracts and macular degeneration. To combat this, you need to wear sunglasses that block UV rays and protect against HEV rays. The choice of frames can also add to the effectiveness of the sunglasses, with the close-fitting wraparound designs being the best as they limit the amount of stray light reaching the eyes from around the lenses.