I have a hen that is broody and she leaves the nest at least once a day to eat and drink. I have noticed that she is getting a bit pink in her comb and wattles but for the most part she is doing great.
When my brooder would get off the nest, I would worry too. One time I worried so much {the eggs had gotten cold} that I chased her back into the coop. LOL But almost every egg hatched, so I worried for nothing. Mother Nature's been at it a little longer than I have, I guess I should have just stayed out of it.