It pays to be sunsmart at 30,000 feet as well as at the beach.
A US dermatologist says is it entirely possible to be burned while on a plane and we should pack sunblock in carry-on bags as a precaution.
Marc Glashofer told Conde Nast Traveler that while aircraft windows block UVB rays, which cause sunburn, UVA rays can penetrate the glass. These rays hit the skin at a deeper level and can potentially cause skin cancer.
It's a problem that's of a particular concern to pilots. In a recent study, JAMA Dermatology found that one hour at 30,000 feet exposed pilots to the same amount of UV radiation from 20-minute tanning bed session.
As the windows in plane cabins are smaller, passengers are less exposed - but it can add up.