How to beat the heat!

My husband and I are training for a half-marathon this fall, but with the 90+ temps going on it is hard to do any running outside. Luckily I work part time for the city which gets me an awesome price on a family gold plus membership to the Rec Plex. So I have been doing my training inside two days a week which means I have to bring the kids up there with me. Well I'm trying my best not to make them dread coming up there so I decided that each day we go I will let them do a fun activity. Tues it was ice skating, which we get free ice skate rentals included with our membership. Thursday it will be swimming inside. So what will this cost us? Nothing but the small fee they take out of my check each payday! That makes for a cheap fun time with the kids and yet I still get my exercise in so we both win!