First of all, these are NOT my animals. They are animals of a good friend of mine who owns many different snakes. She keeps two corns together permanently, and knows they are male and female, both are adults and have bred before. I don't want to hear about her husbandry problems, because I disagree with them too, but she is very stubborn and the animals are healthy and eating fine, just with some husbandry hiccups that most wouldn't agree with.

She calls me today, and tells me she has eggs, and doesn't want them to die this time. Thats where I need your help. What kind of easy incubator can be created in a day that does not cost a lot of money (she's probably not willing to spend too much unfortunately).
Right now, she has a heat pad underneath the hide with the eggs in them, and rheostat on it controlling it at medium. I told her to spray the cage a couple times a day to keep the humidity up, and the mother is wrapped around the eggs.

Can someone give me exact temperatures and a very quick DIY for building a temperature as long with instructions on what to do in the meantime for these animals.

P.S. She does NOT have any thermostats, and I only have one (or I would let her borrow). She strictly uses all heat lamps and sprays constantly.