What is SPF in sunscreen creams? I go to 2500m-4000m altitude. What should I use? And I've heard that SPF more than 55 is not for men. Does more SPF mean more sun protection?
What would be an excellent choice for men? thanks.
As it is stated in this Wikipedia article, the sun protection factor (SPF) roughly describes how the time that your skin is able to protect itself from sunburn is elongated. To take the Wikipedia example:
So, yes, more SPF means more protection. How much protection you need depends on how intense the sun is where you are, how long you are about to stay in the sun, and how sensitive your skin is.
In general one can say, that if you are somewhere with highly reflective surfaces (snow, water...) you need more protection than somewhere in a light forest. Also the higher you are, the more SPF you should take, as in higher altitudes less of the UV radiation is absorbed by the atmosphere. Therefore one cannot give a definite recommendation on what SPF you should use.
Also if your skin requires an SPF of 50 or higher, you will need it – male or not male – and in high altitudes on a glacier you might need it.
If you are totally unsure about what is suitable, I would recommend seeing a dermatologist to find out which skin type you are and what protection will be needed for it.