I grew up in northern California, where it was consistently in the hundreds in the summertime. My dad didn't think he should have to turn on the air conditioning when we had a swimming pool in our backyard; it was our built-in air conditioner.
Swimming is great because there are levels of goals. First, when I was four, it was making it to the other end and overcoming the fear of standing up in front of everybody at a swim meet because I was such a shy kid.
I started swimming when I was four because my brother wanted to join a swim team, and I wanted to do what he did. They said I had to be six, but if I could swim a lap, then I could participate. So I swam a lap, and the rest is history.
It really was my brother who got me involved in swimming. I wanted to be just like him and do everything he was doing.