How to tell when your child is seriously ill

It has been one crazy 24 hours. Shona was up until after 3:00 with a severely congested head. She was so darn miserable and nothing helped, not medicine, not a breathing treatment, nothing. She finally fell asleep out of sheer exhaustion and we got about 3 1/2 hours of sleep. I woke her up figuring she'd miss her first day of school the first week of school, but she got up, was very chipper and happy and other than a slightly stuffy nose, was just fine. I sent her off to school. We had to run to the base to get new I.D. cards after school, and she was sort of a terror for most of it, but then at other times was a doll....like confiding to me as we were picking out a new outfit for her that she's in love with a boy in her class but he doesn't want a girlfriend. Ah, young love. Anyway, I digress. So she was on John's last little nerve the entire trip, hyped up, could not stop talking no matter what she tried and could not focus. I knew she was worn out, the poor thing. She fell asleep in the van on the way home, I brought her in and put her to bed. About an hour later, I got up to check on her, stepped into her room and she was sitting in the middle of the floor. I said "Shona! What are you doing up....(I look around the room).....cleaning??! Of all things! Cleaning her room! She looked awful. She had dark circles under her eyes, she was sniffling again, but there she was cleaning. The funny part was she looked guilty like I'd caught her sneaking into a hidden stash of Christmas presents or something, and she hopped back in bed. I cannot get that child to clean her room even under threats, so I knew she had to be delerious! Maybe I should sleep on the floor next to her bed. Or perhaps I should let her sleep in my room, so if she wakes up with a feverish need to clean, she can do my room next!