Try not to stress so much. Sounds like you have a lot of adrenalin going on. First congratulations on the pregnancy. Be careful handling the chicks and being pregnant. The chicks that are a live just need to be kept warm. You can give save a chick water supplements. Just take the chicks and dip their beak into the water dish. Tomorrow you can get chick feed, they will be ok with no food tonight. They are still absorbing nutrients from just hatching. The water is good because they might be hot from being under the heat lamp. As someone suggested you can use a temporary lamp 65 watt or less and just position it so they can step away if they get to hot. If you have gloves I'd recommend using it to handle the babies. I get more paranoid about pregnancy.
Put the chick or chicks back in the nest with its mama. A cardboard door to keep the chick from hopping out along with a very dark place or nest box ( preferably a dark place) to keep the nest box in so that the hen is still and quite MAY help for a day or two.
The real danger this chick faces now is that it may be imprinted on humans since you could be the first big moving creature or object it saw up close after hatching. In this case it might just as easily jump into freezing conditions or else the fire looking for you who it now thinks of as its mommy, rather than staying with its chicken mother where its safe and warm. Chicks can imprint on radio controlled cars or even on raccoons, that is if the coon isn't hungry at the time.
From the above photo alone I am not optimistic about your chicks chances. Sorry but if it passes at least you may not be to shocked or surprised. If you were trying to hatch biddies I am unsure why you had such an early or else so late hatched chick.
Everyone should remember that chickens do not share our human since of logic and the word LOVE is definitely not in the chickens' dictionary. The simple fact that a hen is sitting on the nest in preparation to lay an egg actually produces less of what we humans think of as the milk of motherly kindness for young chicks, not more mothering instinct or behavior on the hens' part.
Place a little container of SHALLOW water in the opposite side of the box. That way the chick has full access to water.
I think your chick should be fine until morning. Keep the heater on over night but make sure the chick has a cool spot to go to if it gets too hot. If you truly can't manage 1 chick then take him/her to a local pet shop and they should be able to accept it. You could try feeding it the TINIEST bit of soft fruit like a banana, apricot, squeezed blueberries or tomatoe insides.
Let us know what happens
Both the chicks saw the mama hens, the first one seen everyone in the coop and possibly hung out in the coop a while with all the hens and roosters and ran around on the coop floor eating, the second one seen the mama hens but two of them were aggressive towards both chicks, (new mothers) the other one my buff orphington was very accepting of the chicks but not really totally broody yet and was laying on eggs and pre occupied. I didn't want to risk the moody broody mama hens (inexperienced pullet mamas) attacking, or falls, because my nest box has 6 openings, but only 3 nests that a chick can fall from easily. Plus its super cold at night and there's no heat in the nest, just two mean mamas that want nothing to do with the chicks, that just seem to want to finish hatching the rest of the eggs and that's it. There is a heat lamp way above the roosts in the main part of the coop but not warm enough for a chick by itself, and to wet on the coop floor and ground under the straw. I thought it was best to pull the chicks out bring the inside my bathroom where its warm plug the heater in, set up a brooder with towels, save a chick water, I ended up crushing finely hard boiled egg yolk and finely crushed life cereal which is oat based, the chicks are warm, 1/2 heater pad, 1/2 not, happily chirping and pecking at the food and eating.
That's great to hear, I'm sure they'll do well.
Just remember get them chick starter feed as soon as possible.
Be careful, the heater shouldn't be set on high, it could get too hot or even burn the chicks little feet.
I would advise against giving the chicks back to the hen, she is likely to kill them. And probably should never be used as a broody again, either.
Glad to hear the chicks are doing well. As said above, no need to worry about food for the first few days, as they are internally absorbing their yolk sac for that amount of time. Water is a good idea especially if you are using a heat lamp, just dip their beaks in it so they know where and what it is.
Temperature is very important, as chicks have a hard time digesting food, and use more energy to try to stay warm, is the temp is too low. Not sure? Use a thermometer.
When I feed new chicks I will put the food in a shallow heavy dish that they can't knock over, sprinkle a little food in the bottom then tap my fingertip to mimic mom's beak. They get it pretty quick.
The Learning Center has some excellent articles on chick tending.
I got chick starter feed, chick grit today, and a water dish, and a dish for feed and a dish for grit, last night we pulled out an old heat lamp on a tall stand to shine over the cage, the heat pad still on under 1/2 cage. Socialized with a buff orphington mama hen today she's sleeping in a separate cage of the chicks within viewing distance, when she first went in with them to visit the chicks were so happy! She was non aggressive, but accidently stepped or knocked em over a few times, so I figure its best to have separate but close by so she gets use to the idea of babies.