I'm glad to hear that you have a/c in Colorado, cuz when I lived there in the late 80's we didn't and they told us we wouldn't need it. LIARS!! lol That dry heat bakes you dead. Anyway, I have found 2 pilates dvd's at the library that I liked so much I ordered from amazon resellers for like $8 each. Pilates for weight loss by Suzanne Deason, and another title of pilates by Ana Corbin. They both have lovely ocean scenery that gets you past the drudgery of staring into the tv. Floor work, no noise. Just thought I would pass on the titles. They may not be cardio per se, but they get my heart rate up, get me sweatin', and the next morning I FEEL it! It could get you thru until September, which my memory tells me is when the mornings get delightfully crisp in Colorado (at least, in the Springs where I lived).