Heat Wave

I'm currently sitting inside during a 100 degree day here in Connecticut.   The little guy and I have found little to do in these weary conditions.   So far I've come up with the following:

• Water, ok this one is pretty obvious.   We could hit the baby pool at the park or even stick an inflatable pool in the backyard.   A toddlers attention span generally dictates that we're only able to spend about 10 mins in the water and he wants to go do something else.   It's still the best option for a free activity outside of the house though.
• The mall, this is along the same lines of what do we do during a snow storm.   I generally avoid this place during those conditions also.   I have neither the money nor inclination to bow at the altar of consumerism.
• The library, I love the library.  But it became our refugee camp during the past winter.   I'm trying to do all I can to avoid it during the warmer months.

Two more days of 95+ degree days.   I don't mind it, in fact I went for a 4.5 mile run during the peak of it yesterday.   Two year olds tend to be less resident though.   I need ideas people,.   What do you suggest?