unless it is really cold where you are at or she is off more than 30 or 40 minutes you most likely don't need to worry. The surface of the eggs cool rather quickly but it takes much longer for the inside to do the same. My hens routinely are off for 15 minutes at a time with out problem.My blrw is sitting on about 9eggs. She gets off to eat, drink, stretch. But the eggs get pretty cool before she goes back. She's been sitting for about 5 days. She is my first broody that I am letting hatch. Really not sure what to do.