If you’ve been out in the sun without sunscreen for an hour and forty minutes – you’ve suppressed your immune system by 50%. And when the body’s defenses are lowered, that’s what raises the risk of skin cancer… and can make people vulnerable to infections. That’s because too much UV radiation decreases the amount of T-cells, which are a type of white blood cell that help keep our immune system strong. That’s according to the M.D. Anderson Cancer Center at the University of Texas. Share that with someone you know who spends a lot of time outside.