URGENT chicks in school class potential illness

so I’m a teen and at my school we have a class where we raise chicks it’s a good class and they are well cared for I will be adopting 3 chicks this Friday and need help one of the 3 chickens has cold feet and once had diarrhea (no blood just like broun not super runny but still diarrhea)i know this coud be a sine of a potential heath inssue and need advice this chick will go to someone in my family but I can,t quarantine them till Friday when I pick them up due to the fact our school only has one area for chickens I need advice urgently. Shoud i pick them up tomorrow instead I may be able to pick up just the one we have concerns about. Pls help me in just worried Becuse this chick had diarrhea yesterday and has been with other chicks contusly FYI this is my classmates chick there raising that will be adopted by my family. I’m so worried something coud be wrong, i will be buying eltrolites Becuse apprenly they’re good for chicks and cold feet coud be Becuse of lack of elrolites. sorry for the spelling.