This is a link to a written pamphlet I received some years ago.   I made a web page from the information but it goes through the protocol that you should follow in illness.  Like I said the temp can sometimes go down after a larger dose of corticosteroid and then shoot back up in say the afternoon when children get their lower dose.  What I did was take the temperature before every dose and observed when it was the highest the last time Ashley was sick in hospital.  It was shooting up higher in the evening after the lower doses.  

http://congenitaladrenalhyperplasia.org/mb/index.php?msg=0223480541&forum=main