SWINDON CANCER APPEAL: There are three types of skin cancer. The two most common are basal cell and squamous cell carcinomas. They are easily treated and rarely fatal. The third and most dangerous is the malignant melanoma.

In Swindon, there are 30 cases of malignant melanoma and 260 other skin cancers diagnosed a year.

Melanomas can spread horizontally, which gives rise to the superficial spreading melanoma, or downwards where the cells invade the lymph glands, which is much more dangerous.

There is strong evidence that melanomas occur on sun-damaged skin and that people are particularly at risk when they have sudden, short bursts of sunlight on holidays in places where the sun is very strong.

People most at risk from melanoma include those with a high number of moles, with red or fair hair, blue eyes, fair skin and freckles, who tan with difficulty and burn in the sun, and with a history of the disease in two or more family members. If detected early, skin cancer has a 99 per cent cure rate.

Ultraviolet rays are the sun's invisible burning rays. They cause sunburn and in some cases skin cancer.

There are three types of UV rays:

UV-A: These rays penetrate more deeply than UV-B rays into the skin's many layers. They maintain a relatively constant intensity throughout the year and play a part in premature ageing and wrinkles, sunburn and skin cancer.

UV-B: These are stronger during the summer, at higher altitudes and closer to the equator, and are stronger than UV-A rays. UV-B is the most common cause of sunburn, can contribute to the premature ageing of the skin, and can cause cataracts a permanent clouding of the eye that greatly reduces vision.

UV-C: These rays, although the strongest and most dangerous, are normally filtered by the ozone layer and do not reach the Earth.

Sun facts

Protecting your skin during the first 18 years of life can reduce the risk of some types of skin cancer by up to 78 per cent.

You can get burnt on a cloudy day. Up to 80 per cent of the sun's rays can penetrate light clouds, mist, and fog.

Experts warn that one severe sunburn during the first 15 years of life can double the risk of skin cancer.

Snow reflects the sun like a mirror. Fresh snow reflects up to 95 per cent of the sun's rays wearing sun cream is just as important on the piste as by the pool.

You can get sunburnt when you are in the water as it reflects 5 per cent of the sun's rays back on you.

Even dry surfaces reflect the sun's rays. Concrete reflects 10 to 12 per cent of rays.