Sunshine can boost our mood and support vitamin D production, but too much ultraviolet (UV) exposure can cause lasting skin damage. Just one blistering sunburn, particularly during childhood or adolescence, can increase the lifetime risk of melanoma, the most serious form of skin cancer. Repeated sunburn increases that risk further.
UV damage begins before you see or feel a burn. UV radiation stimulates melanin production, causing the skin to tan. A tan is therefore a protective response to UV-induced cellular stress and damage, not a sign that the skin is unharmed. UV radiation, both UVA and UVB can damage DNA in skin cells within minutes of excessive exposure, particularly in very fair skin. Over time, collagen and elastin break down leading to premature skin ageing in people of all skin tones, contributing to wrinkles, sagging and leathery skin although risk levels vary. Time of day, season, altitude and certain medications can also increase sun sensitivity.
UVB mainly affects the skin’s surface (the epidermis), directly damaging DNA and causing inflammation, typically seen as hot, red skin. UVA penetrates deeper into the dermis, generating reactive molecules that can damage DNA, proteins, fats and other cell structures.
The skin can repair much of this damage, but the process is not perfect. If damage is not fully repaired, mutations can accumulate and potentially lead to skin cancer.
There is therefore no completely “healthy tan”. If you want a tanned appearance, sunless self-tanning products avoid the UV exposure associated with sunbathing and sunbeds. However, fake tan does not provide sun protection, so normal sun-safety measures are still essential.
When deciding whether you need protection, check the UV Index rather than the temperature. Cool, breezy or cloudy days can still have high UV levels, with 50–90% of UV radiation potentially penetrating cloud cover. When the UV Index is 3 or above, protect your skin. At extreme levels of 11+, fair skin may begin to burn in as little as 10–15 minutes.
Sunscreen works best as part of a wider approach. Wear lightweight protective clothing where practical, seek shade, and use a broad-spectrum SPF 30 or higher on exposed skin. Most people apply only 25–50% of the recommended amount, greatly reducing the protection they receive. Reapply sunscreen every two hours and after swimming or heavy sweating. A wide-brimmed hat and UV-protective sunglasses provide additional protection.
Although sunburn fades, some molecular damage remains. Skin cells repair much of the damage caused by UV exposure, but the process is not perfect, so cumulative exposure matters.
The key message: enjoy being outdoors but avoid getting burnt. Check the UV Index, seek shade when UV levels are high, cover up where practical and use sunscreen properly. A few simple habits can protect your skin now and reduce the future risk of skin cancer and premature ageing.