It's easy to get sunburn in Tibet. And it can be more than just
uncomfortable. Among the undesirable effects are premature skin
ageing and possible skin cancer. Sunscreen (UV lotion) with a high
sun protection factor (SPF>30), good quality sunglasses and a
wide-brimmed hat are recommended for your protection.
Those with fair skin should bring reflective sunscreen
(containing zinc or titanium oxide) with them. Apply the sunscreen
liberally to your face, taking particular care with nose and lips.
Take careful note of how long the sunscreen will be effective and
reapply as instructed.
(Tibet Travel Expert)