Our southeast (I think) facing house tends to stay cool and this year hasn't been as hot as last year so far.
But I think these are a big contributing factor as well:
Not the guy, but the window he is standing next to. And 8 others windows like them. We've been using our heater less this winter and less this spring and summer as well. And saving on average about $10 each month on our gas bill.
Keeping this up for several decades and the windows would have paid for themselves!