| What it is | Protecting skin & eyes from UV |
| Tools | Sunscreen, UPF clothing, hat, sunglasses |
| Ratings | SPF (sunscreen), UPF (fabric) |
| Worse at | Altitude; on snow & water |
Sun protection is guarding your skin and eyes from ultraviolet (UV) radiation using sunscreen (rated by SPF), sun-protective clothing (rated by UPF), a hat, lip balm, and UV-blocking sunglasses. It’s one of the Ten Essentials because UV exposure intensifies at altitude and reflects off snow and water, causing sunburn, snow blindness, and long-term skin damage.
This is general educational information, not medical advice.
Why it matters
A core Ten Essentials item; UV-blocking glasses prevent snow blindness on snow and at altitude.
Frequently asked questions
What's the difference between SPF and UPF?
SPF (Sun Protection Factor) rates how well a sunscreen protects skin from UVB, the burning rays — SPF 30 blocks about 97%. UPF (Ultraviolet Protection Factor) rates how much UV a fabric blocks — UPF 50 lets through about 1/50th of UV. SPF is for sunscreen; UPF is for clothing.
Why is sun protection one of the Ten Essentials?
Because UV exposure outdoors is easy to underestimate and its effects — sunburn, snow blindness, heat stress, and long-term skin cancer risk — are significant. UV intensity rises with altitude and reflects strongly off snow and water, so even cool or cloudy days at elevation can cause serious burns.
How do you protect yourself from the sun outdoors?
Combine methods: apply broad-spectrum sunscreen (SPF 30+) to exposed skin and reapply regularly, wear a brimmed hat and UPF clothing, use UV-blocking sunglasses (essential on snow to prevent snow blindness), apply lip balm with SPF, and seek shade during peak UV hours. Sun protection matters year-round, not just in summer.
Sources
- Sun safety — CDC
- UV protection — American Hiking Society