The amount of sun exposure required to burn a person depends on that person’s skin type. Someone who is light-skinned might get a sunburn in less than 15 minutes of exposure to mid-day sun. Medications and other factors can also make the skin more susceptible to sunburn.
Moderate cases can lead to temporary disability, and severe cases can lead to swelling, blistering, fever, and dehydration.
The burn is not due to the heat of the sun. It is due to the ultraviolet radiation bombarding the cells in the deeper layers of the skin. Since we cannot feel the radiation, the symptoms appear only after the cells are damaged and become inflamed.
It takes time for inflammation to occur, so a sunburn may not be apparent until after you have gotten out of the sun.
The pain of sunburn also worsens over time, reaching a peak 12 to 48 hours later. Damaged skin later peels off, usually 2 to 7 days later.
Once the skin has burned, there is little that can be done other than providing comfort while the body heals itself. Therefore, prevention is the most important step to take. Use sunscreen and follow recommendations for sun protection.
Sunburn has long-term risks. Blistering sunburns, particularly in children, increase the risk of melanoma skin cancer years later. And ongoing sun exposure, even without burning, leads to premature aging of the skin and other forms of skin cancer (basal cell and squamous cell).
If you do get a sunburn, these measures will provide comfort:
Call your doctor if you have a fever, or blisters, or develop dizziness with the sunburn. Your doctor may recommend the use of dry bandages on the blisters, or other measures.