Summer heat incubating egg

[ShaliniW1985]

I live in the north east of the United States and you wouldn’t think it, but it gets REALLY HOT here in the summer. Almost everyday is in the 90’s or the mid 80’s. Last mo two of my khaki Campbell ducks went broody and sat on two fertile eggs. Unfortunately none hatched. This month one of my khaki Campbell’s was acting odd and was sitting on her nest for a while so I decided to check her eggs, and as I suspected, 4 appeared to be fertile. At this moment two appear to be dead, but the other two are flourishing. The hen has been on and off the nest but mostly off the past few days. Is it possible to hatch these eggs with just the natural heat? They seem like they’re doing fins without a hen on them but is it possible? I have an incubator on the way at the moment but until it gets here could this work? has anyone had any similar experience?
Edit: I have notes on my phone that I can put in here day by day if it helps

 

[nchls school]

The temperatures would need to stay around 100 degrees around the clock so it is unlikely the eggs would hatch as you describe.

 

[ShaliniW1985]

The temperatures would need to stay around 100 degrees around the clock so it is unlikely the eggs would hatch as you describe.

Well it was worth a shot. My incubator should be here on the 5th but idk I’d they’ll make it that long. Thanks for the help.

 

[ShaliniW1985]

The temperatures would need to stay around 100 degrees around the clock so it is unlikely the eggs would hatch as you describe.

just one more question, since my hen has been off the nest the eggs still seem to be doing ok. My incubator is supposed to be here on Wednesday so how long do you think they’ll be able to stay alive for?