What does sunscreen protect against?
UV radiation can damage skin cells and their DNA. Most skin cancers are caused by too much UV exposure from the sun or tanning beds. Repeated exposure also contributes to early wrinkles, age spots and loss of skin elasticity. UVA rays contribute to premature aging and can pass through window glass. UVB rays are the main cause of sunburn. Both can contribute to skin cancer, which is why sunscreen should protect against both.345
Do you need sunscreen when it is cloudy?
Yes. UV rays reach you on cloudy and cool days, and sun protection matters throughout the year. Water, sand and snow reflect UV rays and increase exposure. You cannot see or feel UV radiation, so temperature is not a reliable guide. Apply sunscreen to uncovered skin every day you will be outside. Check the local UV index, which describes the strength of UV radiation: use sun protection when it reaches 3 or higher.345
What sunscreen should you choose?
Choose broad spectrum sunscreen with SPF 30 or higher and water resistance. Broad spectrum means protection against UVA and UVB; SPF mainly measures protection against sunburn from UVB. No sunscreen blocks all UV radiation, and a higher SPF does not remove the need to reapply. For sensitive skin, mineral sunscreen containing zinc oxide or titanium dioxide is a recommended option.156
How do you apply sunscreen properly?
- 1Apply sunscreen generously before going outdoors, following the label. General application guidance is 15 minutes before sun exposure.
- 2Cover all exposed skin. An average adult needs about one ounce for full body coverage. Applying too little reduces protection.
- 3Include your ears, neck, hands, tops of feet, hairline and exposed scalp. Use an SPF lip balm for your lips.
- 4Reapply at least every two hours outdoors, and after swimming, sweating or towel drying. Follow the label's water resistance instructions.
Lotions, creams, gels and sticks are all options, because apparently even sun protection needs a menu. Directions differ between forms. Never spray sunscreen directly onto your face, and remember that water resistant does not mean waterproof.6
Who needs extra care?
People of every skin tone can get skin cancer. Take extra care if you burn easily, have many moles, have a family history of skin cancer or spend substantial time outdoors. Sun protection also reduces the risk of another skin cancer if you have already had one. Some medicines increase sun sensitivity; ask your pharmacist or doctor about precautions for your medication. Keep babies under six months out of direct sunlight and ask a doctor before applying sunscreen to them.12367
What else protects you?
Seek shade, limit midday sun, and wear clothing, a broad brimmed hat and sunglasses with UV protection. Do not use sunscreen to extend your time in the sun. Sunlight helps your body make vitamin D, but tanning beds are not a safe way to obtain it. People with very little sun exposure should consider oral vitamin D supplements.34
If you get sunburned, stay out of the sun until redness has gone. Seek medical help if you feel unwell or have severe swelling or blisters. Report a new mole, growth or lump, or changes in a mole's size, shape or colour, to your doctor promptly.7
