I'm sure there's not a working mum out there who hasn't packed their kid off to daycare / preschool / school etc knowing they weren't quite 100% well but not able to do much about it. (And if there are, I don't think I want to know, as I feel badly enough already lol). I faced that today - Billy still had a cold & was a bit whingy but I had to go and train - it's very hard to call in sick when you're the teacher!
And sure enough at 3pm I got the call from preschool - "Billy's just woken up with a temperature of 38, do we have your permission to give him Panadol?"... Luckily I'd finished for the day and was on the way home, so was able to pick him up quite soon after and bring him home. BTW he seems fine apart from running a temp - eating, running around etc, so who knows! Pete has arranged to stay home with him tomorrow though, just in case.