The RCH in Vic currently recommend not treating a fever until 39C, at which time you should administer Panadol or Nurofen. Is your little bloke rousable and does he have a rash? If he is just generally miserable and it is getting near bed time, I would administer Panadol and watch him for the next hour or so. If he is not rousable, has a rash or is having trouble breathing I would take him to A and E. If your Mummy Radar is telling you that something is very wrong, it can't hurt to take him, better safe than sorry!