Temperature and altitude limits are generally included in your owners manual. If they are not; contact the support section of the manufacturer for the specifications.
A laptop can be an expensive investment, and buying a refurbished can appear to be an attractive option to lower that expense. It can be completely safe to buy a refurbished laptop, but there are...
It IS NOT SAFE AT ALL FOR MEN there are waves of radiation is not scientifically strong enough to hurt you. However if you are a male, I would suggest putting a case under your laptop if you have it...