What's considered a high temp for children that you should take them to hospital?

Age dependent. Under 60 days old, all temps > 100.4f need to be evaluated in the office or ed. From 60-90 days this temp should still at least warrant a call to the pediatrician. Acute fevers are important but in older kids, fevers >101 are pretty common, and almost never warrant the ed; consult your peds office for guidance with any severe illness.