Just watch them. They can get runny poo if they are drinking a lot. If you don't have a thermometer in the brooder get one in there, because you should keep track of the temperature.
I'm sure they are fine. Wash the pasty butt, and watch the rest, and relax. With little chicks it is easier to harm them trying to help, than kill them off by natural means.
Case in point: I accidentally dropped the brooder lamp on mine. The whole darn thing. I was horrified. I picked up the one it sqashed flattest and cried. It wiggled and peeped. I replaced the brooder lamp, and held it a while crying because I had killed it. But could't bring myself to put it out of it's misery. After a while it stood up shook itself and started crying to it's buddies. I put it back in the brooder and it is fine. Truly fine- you can't tell it from the others.
They are extremely fragile, and yet, sturdier than you'd ever guess, both at the same time. A real enigma.