How long can you usually stay in the sun before getting sunburned?

What type of sun protection do you use? Why should you re-apply suntan lotion during the course of the day?

In which parts of the world are severe sunburns most likely?

Can you sunburn on a cloudy day?

Would an SPF of 200 make any sense?

Why do people sunburn faster when they are playing on the water,
on snow, or at the beach?