The sun is the main cause of skin cancer, the most common form of cancer in the United States. There will be a million new cases of skin cancer this year. Skin cancer can and does occur in children and young adults, but most of the people who get skin cancer are older. Older people get skin cancer because they have already received too much of the sun's damaging rays. Your skin remembers each sunburn and each suntan year after year.

Most of our sun exposure - between 60 percent to 80 percent - happens before we turn 18 years of age. That's because children spend more time outdoors than most adults, especially in the summer.

All skin cancers are harmful and some, especially malignant melanoma, can be deadly if left untreated. Malignant melanoma is the second most common form of cancer in women 25 to 34 years old. Sun exposure in early childhood and adolescence contributes to skin cancer.

Research has shown that two or more blistering sunburns as a child or teen increase the risk of developing skin cancer later in life. It is very important, therefore, to protect babies and children from sunburn. Do this by making sun protection a regular family event. You can be the best teacher by practicing sun protection yourself and teach all members of your family how to protect their skin.

It's up to you to protect your child's skin. Sunburns hurt. Sunburns can also cause dehydration and fever. Too many sunburns and too much sun exposure over the years can cause not only skin cancer, but also wrinkles and possibly cataracts of the eye.

Babies under 6 months of age need extra protection from the sun. Babies have sensitive skin that is thinner than adult skin. This causes them to sunburn more easily than an adult. Even babies with naturally darker skin need protection. Since young children are more vulnerable to the sun, here are some specific rules for children younger than 1 year old:

• Babies younger than 6 months should be kept out of the direct sunlight. Move your baby to the shade or under a tree, umbrella or the stroller canopy.
• Dress your baby in clothing that covers the body, such as comfortable lightweight long pants, long-sleeved shirts, and hats with brims that shade the face and cover the ears.
• If your baby gets a sunburn and is younger than 1 year of age, contact your pediatrician at once - a severe sunburn is an emergency.
• For babies younger than 6 months of age, the risks or benefits of sunscreen use are not yet known. If your baby needs to be outdoors, discuss sunscreen use and other options with your pediatrician.
• For babies older than 6 months of age, choose a sunscreen made for children.

For children older than 1 year old and all family members, follow these simple rules to protect your family from sunburns now and from skin cancer later in life:

• Choose sunscreen that is made for children, preferably waterproof. Before covering your child completely, test the sunscreen on your child's back for a reaction. Apply carefully around the eyes, avoiding the eyelids. If a rash develops, talk to your pediatrician.
• Select clothes made of tightly woven fabrics. Clothes that have a tighter weave - the way a fabric is constructed - generally protect better than clothes with a broader weave. If you're not sure about how tight a fabric's weave is, hold the clothing up to a lamp or window and see how much light shines through. The less light, the better. Clothing made of cotton is both cool and protective.
• When using a cap with a bill, make sure the bill is facing forward to shield your child's face. Sunglasses with UV protection also are a good idea for protecting your child's eyes.
• If your child gets a sunburn that results in blistering, pain or fever, contact your pediatrician.

Here are some additional sun safety tips that apply to all members of your family:

• The sun's rays are the strongest between 10 a.m. and 4 p.m. Try to keep out of the sun during these hours.
• The sun's damaging UV rays can bounce back from sand, snow or concrete; so be particularly careful in these areas.
• Most of the sun's rays can come through the clouds on an overcast day; so use sun protection even on cloudy days.
• When choosing a sunscreen, look for the words "broad-spectrum" on the label - it means that the sunscreen will screen out both ultraviolet B (UVB) and ultraviolet A (UVA) rays.
• Choose a water-resistant or waterproof sunscreen. Sunscreens that are "waterproof" should be reapplied every two hours, especially if your child is playing in the water.
• Zinc oxide, a very effective sunblock, can be used as extra protection on the nose, cheeks, tops of the ears and on the shoulders.
• Use a sun protection factor (SPF) of at least 15.
• Rub sunscreen in well, making sure to cover all exposed areas, especially your child's face, nose, ears, feet and hands, and even the backs of the knees.
• Put on sunscreen 30 minutes before going outdoors - it needs time to work on the skin.
• Keep your child completely out of the sun until the sunburn is totally healed.
• Sunscreens should be used for sun protection and not as a reason to stay in the sun longer.