Although summer officially begins on June 21, many begin their summer on May 24 -- heading for the beach or boats to have fun in the sun.

Sunshine provokes an instinctively positive response in most of us. The word itself is synonymous with cheerfulness.

In fact, many people who spend most of their days indoors or live in regions of the world which receive little sunlight can be more susceptible to suffer from depression. Vitamin D deficiency can also be widespread among those who spend most of their days in-doors.

The effect of sunlight on bacteria was proven in 1877 by Dr. Arthur Downes and Thomas Blunt, whose studies showed its ability to kill bacteria. This discovery influenced the design of some hospital wards.

While too little sunlight can cause health problems, too much sunlight is also damaging. This is especially true today as the level of ultraviolet light from the sun is much higher than it was 50 or 100 years ago.

This is due to a reduction of ozone in the Earth's atmosphere as a result of pollutants. Ozone serves as a filter to screen out and reduce the amount of UV light that we are exposed to.

With less atmospheric ozone a higher level of UV light reaches the Earth's surface. Other influencing factors include elevation, latitude and cloud cover. However even on a cloudy day, 80 percent of the sun's harmful UV rays come through.

Ultraviolet light is stronger as elevation increases. The thinner atmosphere at higher altitudes cannot filter UV as effectively as it can at sea level.

The rays of sun are also strongest near the equator and at summer solstice.

However in many parts of the world UV levels are much higher than might be expected due to ozone depletion.

The effect UV light has on your skin is dependent both on the intensity and the duration of your exposure. How your skin reacts to the amount of exposure received is related to your genetic background. Tanning is your skin's response to UV light. It is a protective reaction to the sun.

In tanning certain cells in the skin become more active, producing a dark pigment (melanin) that absorbs UV radiation. When it comes to sunlight, moderation is the key. In fact, people who get almost no sun exposure are at a higher risk for skin cancer than those who get regular, moderate early morning sunshine. So this summer practise good sun sense.

Prevention is the key.

Minimise midday exposure to the sun.

Do not use tanning beds. They have been implicated in skin cancer, accelerated aging of the skin, cataracts and immune system disorders.

Wear protective clothing including a wide-rimmed hat -- baseball caps do not protect the neck.

Use a sunscreen with SPF 15 or more. Don't forget to apply SPF lip balm.

If your skin is loaded with carotene A, vitamin C, E and B complex, your skin stands much less chance of damage by the sun. You can also add to your sunscreen the contents of one capsule each of -- vitamin A, vitamin C, vitamin E and selenium to help prevent free radical damage to the skin.

After sunning, add these antioxidants to whatever skin cream you use for added protection and to aid in preventing wrinkles. Antioxidants like pycnogenol, ginkgo, and alpha lipoic acid protect your skin.

Drink plenty of water before, after and during sun exposure to replenish and moisturise your skin from within.

If you do get burnt: Aloe Vera is one of the most effective treatments for any kind of burn. It is even used in the burn unit of some hospitals.

To use the fresh plant cut off a lower leaf near the central stalk, cut off any spines along the edge, split the leaf lengthwise, score the gel with the point of your knife and apply it directly to your skin.

It will soon soak in and provide immediate soothing relief. Reapply every hour until the pain is gone.

If you use a commercial product make sure it contains no alcohol, mineral oil or colouring. Health stores generally stock pure aloe vera gels. New research shows healing results for skin cancer.

The juice of the aloe has been shown to be effective for stomach ulcers, acid reflux, arthritis, allergies and eczema. Aged aloe juice is widely used in AIDS treatment to block the HIV movement from cell to cell.

For burn relief you can also apply yogurt, black tea, vinegar or lavender oil.

Apply grated apple to burned eyelids for fast relief.

Essential fatty acids such as those found in evening primrose oil improve sundamaged skin.