My 14 year old daughter became ill last Sunday night with a sore throat and sinus congestion. She also has a knack for getting sinus infections quite easily, so I keep a close eye on things. We've experienced situations in the past with fluctuating temps and extreme tiredness. I can understand that without vomiting or fever, you wonder if doubling the dose is really necessary. I have consulted the endo and occassionly when her illness seems to be borderline (slight fever, no vomiting, and extremely tired), I have upped her meds by half of the regular dose for a day or two. It seems to help. Talk to you doctor. By the way, I ended up taking my daughter to the doctor's on Wednesday. By that time, she had a sinus infection. Take care and talk to you doctor. Peg D.