@AutumnRose1 At the moment, that decision would be down to the individual school. Schools obviously have insurance for trips not going ahead, but this wouldn't pay out at the moment unless the destination closed (as the Louvre has done).
Personally, I think schools should be looking at cancelling foreign trips and residential trips at least, but again this is difficult to do without being able to refund parents. It would be a lot easier if the government published advice telling them not to go (I think the government should do this btw, the risk of quarentine/not being able to get back is problematic on its own).
I also think schools shouldn't be taking children to large events, but again it can be difficult to cancel these at short notice. Again, if the government said (like the the french one) no gatherings above X amount of people, this would help.
I don't think there's much more risk to going on a local trip to being in school though unless there are diagnosed cases in the area.