I tend to like doing stuff around the yard too, though it's a double edge sword, if it's hot out and I get all sweaty and crap I just don't enjoy it as much and get tired fast, but I just work at my own pace, if I want to go inside and stand in front of a fan or the AC for 10 minutes to cool off, I go do that, then go back outside. I find I don't tollerate the heat as much as I did when I was young.
I do want to build a shed though, that will make a fun summer project. Debating on doing it this year or waiting, as there's lot of other things I could spend that money on like a new patio door, which I badly need.