Sunlight can help our mental outlook and help us feel healthier. For people who have arthritis, the sun's warmth can help relieve some of their physical pain. Many people also think that a suntan makes a person look young and healthy. But sunlight can be harmful to the skin, causing immediate problems as well as problems that may develop years later.

A sunburn is skin damage from the sun's ultraviolet (UV) rays. Most sunburns cause mild pain and redness but affect only the outer layer of skin (first-degree burn). The red skin might hurt when you touch it. These sunburns are mild and can usually be treated at home.

Skin that is red and painful and that swells up and blisters may mean that deep skin layers and nerve endings have been damaged (second-degree burn). This type of sunburn is usually more painful and takes longer to heal.

Other problems that can be present along with sunburn include:

• Heatstroke or other heat-related illnesses from too much sun exposure.
• Allergic reactions to sun exposure, sunscreen products, or medicines.
• Vision problems, such as burning pain, decreased vision, or partial or complete vision loss.

Long-term problems include:

• An increased chance of having skin cancer.
• An increase in the number of cold sores.
• An increase in problems related to a health condition, such as lupus.
• Cataracts, from not protecting your eyes from direct or indirect sunlight over many years. Cataracts are one of the leading causes of blindness.
• Skin changes, such as premature wrinkling or brown spots.

Your skin type affects how easily you become sunburned. People with fair or freckled skin, blond or red hair, and blue eyes usually sunburn easily. Your age also affects how your skin reacts to the sun. The skin of children younger than 6 and adults older than 60 is more sensitive to sunlight.

You may get a more severe sunburn depending on:

• The time of day. You are more likely to get a sunburn between 10 in the morning and 4 in the afternoon, when the sun's rays are the strongest. You might think the chance of getting a sunburn on cloudy days is less, but the sun's damaging UV light can pass through clouds.
• Whether you are near reflective surfaces, such as water, white sand, concrete, snow, and ice. All of these reflect the sun's rays and can cause sunburns.
• The season of the year. The position of the sun on summer days can cause a more severe sunburn.
• Altitude. It is easy to get sunburned at higher altitudes, because there is less of the earth's atmosphere to block the sunlight. UV exposure increases about 4% for every 1000 ft (305 m) gain in elevation.
• How close you are to the equator (latitude). The closer you are to the equator, the more direct sunlight passes through the atmosphere. For example, the southern United States gets 1.5 times more sunlight than the northern United States.
• The UV index of the day, which shows the risk of getting a sunburn that day.

Preventive measures and home treatment are usually all that is needed to prevent or treat a sunburn.

• Protect your skin from the sun.
• Do not stay in the sun too long.
• Use sunscreens, and wear clothing that covers your skin.

If you have any health risks that may increase the seriousness of sun exposure, you should avoid being in the sun from 10 in the morning to 4 in the afternoon.

Check your symptoms to decide if and when you should see a doctor.