Shaun, my daughter has worn a bracelet from Medic Alert since she was diagnosed.  I would suggest inscribing it with something like "cortisol deficient - give hydrocortosone in emergency" or something similar.  What I like about Medic Alert is that they have the toll-free number to call where emergency personnel can get all the information they need about your medical condition - medications, doctors' names and phone numbers, parents' name and  phone number, etc  We have never had to rely on this up to this point, but I can see where this may come into play  now since my daughter is 12 yrs. old and involved in many more school activities and becoming more and more independent.  There is an annual fee for Medic Alert, but considering your child's wellbeing is at stake, it certainly seems worth it to me.