This is why it is so important to go to the hospital during a fever and vomiting. More importantly during a fever. You must give the solucortef injection first. The low sugar can happen during an adrenal crisis especially if you do not give the injection. Again do not wait for the ambulance or the the trip to the ER - it could be too late. If you do not have solu-cortef injection  - GET IT!!  The priority is the solu-cortef - then have the ER people do a finger pick for the sugar before they draw the labs.  And start the IV immediately. Sodium IV is the most important ... and sugar only if the finger pick show low sugar. Low sugar can happen but not always.