occasional exposure. one bad sunburn preexposes you to it for life. you can get it because it runs in your family. you may be predisposed genetically to it. may not only have to do with burn. >> use sunscreen it will protect you. >> it is false sunscreen alone will protect you. people lather it on i am safe i am going to stay here for hours. they don't replace it they go swim in the water they come out. you have got to use a lot of sunscreen and use it repeatedly. don't think it's enough. it's a first step. wear a hat, use an umbrella. sunscreen is great, it's not enough. >> don't sun bathe for starters. >> dr. mark seigel separating fact from fiction. >> 26 after the hour. still to come he's one of the most popular talk radio hosts in america.