Hey Rich,
from what you described, sounds like everything is good..
as for the heat waves !!! it could be possible, they can take a little heat but not for extended periods of times.. so, is 4 days too long ?? if at night temps went back down and you are misting , which helps bring the temps down.. could be no problem .. then again, it could have triggered an early birth.. but this could be caused from different reasons too, too hot, not hot enough, stress..
I Have central air and my snake room is on the basement level ,so summer time tends to stay cool in the house and I add a small heat radiator in the room and humidifier for the winter just to keep the room at 78.. it doesn't need to work too hard with all the cages in there, but does help .
but another thing you could do is to add extra support for the female, more vines or perches to help support her weight ,if you haven't already.. that with a good 90 deg hot spot should help get her to term with fully developed little red babies
also, after I have noticed locks I make sure not to skip meals and let them feed more as they get bigger until they go off feed..this might also help assure they have the energy reserves to make it to the end..
going to start matching up 3 females this weekend.. hope the males are looking for dates :-D