 Never go on an airplane without this first. UV radiation actually increases with altitude. In airplane windows, they don't protect against UVA rays. One study found that airplane pilots have a higher risk of skin cancer. Just one hour in the cockpit is like spending 20 minutes in a tanning bed. So if you prefer the window seat, make sure you slather on a broad spectrum sunscreen with a high SPF. And if it's a long flight, don't forget to reapply every two hours.