HI, welcome and "WOW" what a crazy find
That popping noise sounds like it was the start of an RI and the quickest cure to a minor RI is to raise the heat and it looks like that happened by accident.
Usually by the time the snake starts gasping for air by gaping its mouth the RI is pretty advanced and would require a vet visit. Doesn't sound like that's the case here. You can check its mouth for foaming/bubbles and excessive fluids.
Since you were able to "pop" them then you probably could check for an RI.
I'll try to explain how.. gently grasp the snake right behind the head by wrapping your fingers around his/her neck while placing your thumb under its head. With a little bit of pressure, slide your thumb sideways to pull down its lip on one side. I do it one handed but it might be easier to use your other thumb. Your not trying to open its mouth. Your trying to get the bottom lip to move down just a bit to peek inside the gum area. If there is foam/bubbles or mucus then it has an RI. You can also see if its anemic by the color of the gums. They should be at least a light pink but not white.
As Rich mentioned, Your Boas are a tropical snake so its heat requirement is more than north American snakes. Due to that though what I've seen a lot is people actually overheating them thinking and feeling (cold to the touch) that they need more heat than necessary.
Congrats on your upcoming baby!!
You want to use the utmost care in hygiene. Your snakes will continually be in contact with their own fecal matter. Sanitizing your hands after any contact with them or the tubs is a must !! The snakes should never come in direct contact with your newborn. Also snakes are great escape artists so I would doubly secure their tubs.
Looks like I was typing this as so was Nanci........
IMHO>....I would only go to the higher temps recommended if you can verify that she has a RI. if not then I'd keep it at 90 hot side max. My past experience has told me that RTB's (red tail boas) are more susceptible to RI's if they're kept at high temps for long periods then their is a sudden drop is temps even to the 70's.