Good Point, I always use sun block, and its very rare that we get the chance to take our shirts off in Yorkshire!
Check this site out for the dangers. The guys in the photo died at 35 and his story has been used in awareness ads on tv for the past couple of years. Watch the ads, at first I thought he was an actor until they said he had died. I then googled him and found out it was for real.
www.cancerwa.asn.au/prevention/sunsmart/mediacampaigns/John