At night - once the outdoor temps drop below the temp indoors - I suggest opening windows and putting fans in one or two of them blowing outward. This way the fans will pull the hot air out, while cooler air will pour in through all the other windows. If there is a breeze outside, put the fans in the windows on the opposite side of your condo, so that the breeze works with you, instead of against. Early-early in the AM, before the temps start to rise, shut off the fans and close the windows up tight and curtain them. Using the fans this way is much more efficient than having them blow inward - the house cools off much better and stays cool longer, in my experience!