As you said, the first three days are the most critical. The dosage really tapers off after a week and temperature is less of a concern. If its a small heat wave, probably not necessary to remove things if you are far along in the treatment. Increased ventilation is always good, but make sure that the front entrance is completely open and unobstructed as that is the most important. I would go with option 1 or 3 in your case.