A couple of weeks ago a good friend lost her little boy (2) to meningococcal meningitis. Although he had been ill and had a temperature, he had no early onset rash. Sadly by the time a rash developed and they got him to hospital it was too late.
At the time, even the doctors said had they brought him in earlier he might well have been sent home with paracetamol.
There are no guarantees that you can catch a disease like this which causes such a rapid deterioration in young children, but, you can arm yourself with the information that NICE say that health professionals use when they are trying to make those decisions about feverish children.
The whole guidelines from NICE are on a pdf document here
www.nice.org.uk/nicemedia/pdf/CG47Guidance.pdf
its pretty dense and aimed at healthcare professionals.
I took the "traffic light" (i.e. high/medium/low risk symptoms) table from it and have pasted it here
opheliabottom.wordpress.com/
I hope you find it useful.