Today is the first day of summer. The first bikini hit the beach back in 1946, giving sun-bathers lots more skin to tan, and girl-watchers lots more girl to watch. Years of sunburns have taught us that beautiful tans lead to early aging and serious skin problems. Sunburns cause skin to age faster and increase the chances for skin cancer. While there's no safe way to tan, you can protect yourself by wearing a sunscreen, SPF 15, or higher. Use it year-round, rain or shine, because UV rays pass through clouds and through clothes, too. "SPF" stands for sun-protection factor. These numbers, multiplied by 10, tell how many minutes it's good for. SPF 15 lasts 150 minutes, SPF 30, 300 minutes, and so on. So decide how long you'll be on the beach, wearing or watching bikinis, and plan accordingly. And that's the On The House tip for today.