I'm reading there is no air conditioning at this resort. How much of an issue is this in the middle of summer?

There are nice Mitzubishi air conditioning units installed in every condo, but you must pay an "optional" daily fee of $15.00 if you want them turned-on during your stay. I recommend you pay for the air if you are visiting in the months of June and possibly into September, as the Tradewinds almost stop completely during that time.