Quoting SwanFoundNemo:" Ive been doing my Zumba on Kinect everyday for the past 3 weeks. When I first started I could barely ... [snip!] ... to wait until the temperature cools down, or my next update will be titled "Idiot passes out trying to run in 115 degree heat"!"
Here's a pretty cool article I had read in Today's Parent (Canadian edition). This may help get you motivated when the weather cools. Looks pretty easy...I'm going to try it after I have my LO (obviously not right away....I'm not THAT ambitious). Enjoy!