Obviously not all at the same time 
I have just come across something that says:
Conditions where there is no recommended period to be kept away from school (once the child is well):
influenza; cold sores (HSV); molluscum contagiosum; ringworm (tinea); athlete's foot; roseola; slapped cheek disease (parvovirus); warts and verrucae; conjunctivitis; glandular fever; head lice; non-meningiococcal meningitis; thread worm; tonsillitis; hand, foot and mouth disease
Would you take (once the child is well) to mean has not got a temperature?