The guidelines are utter nonsense.
Fair enough to send a child in if they have a bit of a cold or something but with a high temperature? No way.
We had parents who kept sending their child in despite the fact that she had viral meningitis and was hallucinating purely because neither wanted to have time off work. It's daft.
People, and schools, need to use their common sense. And that magic 90% attendance figure should only apply to unauthorised absences. Mine were off loads in the first 3 years of school as they seemed to catch everything going.