What should I do if I get sunburned when I travel? I went out to travel and basked in the sun all day, but I still returned to the hotel.

You have moderate sunburn, so you'd better go to a hospital for professional care. If it's inconvenient to go to the hospital, you'd better apply a moisturizing mask, or find a drugstore (supermarket) to buy some aloe moisturizing cream and aloe repair liquid, and apply it once every hour or two to reduce sunburn.

Generally, the skin will turn black after sunburn, but people with good looks will basically recover in one winter, so don't worry about it.