Thanks to a sunscreen we can be in the open sun for a long time and do not get sunburnt. However, even the cream is not a panacea - it can come off, chemically modify and lose the effect. We also often remember to use the sunscreen again when it becomes too late. At the beginning of a hot beach season a special bracelet appears on the market. It allows to monitor the UV quantity obtained and to take actions in time. Doctors and beauticians do not recommend tanning at all as...