Do I need sunscreen when it is below freezing?

Why cold weather does not cancel sun protection

UV rays can reach you on cool and cloudy days, so temperature and cloud cover are not reliable reasons to skip protection. The thermometer measures cold, not UV exposure, which is an inconvenient gap in its qualifications. UVA penetrates deeper into skin and is more constant throughout the year than UVB. Prolonged UV exposure contributes to premature skin ageing and skin cancer; sunburn is a sign of excessive exposure over a shorter period.24

Skiing and snowboarding deserve particular attention because higher altitude and UV reflected from snow increase sunburn risk. Snow reflects UV as well as looking scenic, so the view comes with extra exposure. Protect exposed skin even when the air feels bitterly cold.1

Check the UV index, not just the temperature

Check your local UV index in a weather app or website before heading out. The index measures the intensity of solar UV reaching the ground, from 0, low, to 11 or higher, extreme. At 3 or above, protect your skin from excessive sun exposure. For winter activities around snow or at altitude, keep exposed skin protected rather than using the freezing temperature as your deciding factor.123

Do not wait for a UV Alert to act. In the US, that alert requires a forecast index of at least 6 that is also unusually high for the date. A day can call for sun protection without qualifying for an alert.3

How to apply sunscreen before going outside

1. 1Choose a broad spectrum, water resistant sunscreen with SPF 30 or higher. Broad spectrum means protection against both UVA and UVB. In the UK, look for at least four star UVA protection or the UVA circle marking.
2. 2Apply generously to all skin not covered by clothing at least 15 minutes before exposure. Include your face, ears, nose, neck and any exposed hands. Protect your lips too.
3. 3For an outing long enough to risk burning, apply twice: 30 minutes before leaving and again just before going out. Applying sunscreen too thinly reduces protection.
4. 4Reapply at least every two hours while outdoors, and after sweating, contact with water or towel drying. Reapply when sunscreen has rubbed off, even if the product is water resistant.

Keep covered skin covered

Use sunscreen alongside clothing and shade, not instead of them. A winter coat covers plenty of skin, but its job description does not include the bits sticking out. Tightly woven clothing offers better sun protection, and a brimmed hat shades the face, ears and neck. Wear sunglasses that block UVA and UVB; wraparound styles also limit light entering from the sides. Shade reduces exposure, but keep sunscreen and protective clothing in use there.2

Who needs extra care?

Winter sun protection applies to every skin tone. Be especially careful with a personal or family history of skin cancer, skin that burns easily, or frequent outdoor exposure. Some medicines, including certain antibiotics, and some topical products can increase sensitivity to UV. For babies under six months, prioritise keeping them out of direct sunlight and using protective clothing rather than sunscreen.1245

Protect against cold injury too

Below freezing, protect your face with a scarf or face mask and wear a warm hat and insulated gloves or mittens. Frostbite begins with redness and stinging, burning, throbbing or prickling, followed by numbness. Head indoors immediately if those symptoms occur. Warm affected skin gradually with warm water or a warm washcloth; do not rub it or use hot water. Go to an emergency room immediately if sensation does not return or the skin turns gray.6