Key takeaways
- Sun protection guards against the sun's UV radiation — sunburn, eye damage, aging, and skin cancer.
- UV intensifies at altitude and reflects off snow and water, raising outdoor exposure.
- It's one of the Ten Essentials.
- Combine methods: UPF clothing, sunscreen, SPF lip balm, a brimmed hat, and UV-blocking sunglasses.
This is general educational information, not medical advice. Consult guidance from health authorities like the CDC and dermatologists for sun safety.
What sun protection is
Sun protection is the set of measures used to guard against the sun’s ultraviolet (UV) radiation, which causes sunburn, eye damage (including snow blindness), premature skin aging, and skin cancer. It’s one of the Ten Essentials, and especially important outdoors.
Why it’s critical outdoors
UV exposure intensifies with altitude (less atmosphere to absorb it) and reflects off snow and water, dramatically increasing your dose. High, snowy environments are extreme-UV — leading to severe sunburn (even under the chin and nose) and snow blindness if you’re unprotected.
How to protect yourself
- Clothing — sun-protective UPF-rated long sleeves and a brimmed hat for reliable, reapplication-free coverage.
- Sunscreen — broad-spectrum, reapplied regularly (especially when sweating).
- SPF lip balm.
- Sunglasses — UV-blocking, or glacier glasses on snow.
On a glaciated peak, a mountaineer wears a UPF sun hoody, a brimmed hat, and glacier glasses, and applies sunscreen to their face, ears, and under their nose — protecting against the intense, snow-reflected UV that would otherwise cause severe sunburn and snow blindness.
Sun protection pairs with managing heat to avoid heat illness on hot, exposed days.
The bottom line
Sun protection guards against UV radiation — which causes sunburn, eye damage, aging, and skin cancer, and intensifies at altitude and off snow and water. One of the Ten Essentials, it's best done by layering methods: UPF clothing and a brimmed hat for reliable coverage, sunscreen and SPF lip balm for exposed skin, and UV-blocking sunglasses (or glacier glasses on snow) for your eyes.
Frequently asked questions
What is sun protection and why does it matter outdoors?
Sun protection is the set of measures that guard against the sun's ultraviolet (UV) radiation, which causes sunburn, eye damage, premature skin aging, and skin cancer. It's especially important outdoors because UV exposure intensifies with altitude (roughly increasing as you climb higher) and reflects off snow and water, dramatically increasing your dose — which is why it's one of the Ten Essentials.
What are the best ways to protect yourself from the sun?
Combine methods: wear sun-protective (UPF-rated) clothing including long sleeves and a brimmed hat, apply broad-spectrum sunscreen to exposed skin and reapply regularly (especially when sweating), use SPF lip balm, and wear UV-blocking sunglasses (or glacier glasses in snow) to protect your eyes. Seeking shade and timing exposure also help. Clothing and a hat provide reliable, reapplication-free coverage, complemented by sunscreen on what they don't cover.
Why is sun protection critical in snow and at altitude?
Because snow reflects a large fraction of UV back up at you, effectively doubling your exposure, and UV intensity rises with altitude as there's less atmosphere to absorb it. This combination makes high, snowy environments extremely high-UV, leading to severe sunburn (even under the chin and nose) and snow blindness if you're unprotected. Mountaineers and snow travelers need diligent sun protection, including high-protection glacier glasses.
Sources
- Sun safety — CDC
- UV protection — American Academy of Dermatology