My son is 2y6mos. He started to get unwell on Saturday night and he seems to have got progressively worse.
I have had a nasty chesty cough for the last 2 weeks and although I tried not to pass it on I assumed he caught it because on Saturday evening he started chesty coughing as well. He went to bed around 8 and woke me up at 12.30, crying. I went to him and he was very hot to touch so I gave him some Calpol and cold milk and he went back to sleep. The next morning he slept until after 9 (so 13ish hours, he normally has about 11) and woke up with a raspy voice but seemed alright in himself.
Yesterday:
He normally hardly ever naps any more, but about 3 hours after waking up he was rubbing his eyes and getting irritable. He refused any lunch, and was falling asleep by 1 so I put him in bed. I went in to check on him regularly, he kept waking up, crying and going back to sleep. He seemed hard to properly rouse and a bit confused. He was on and off very hot and when I took his temperature it fluctuated between 37.6 (ok) and 38.6 (not ok) with an under arm thermometer.
He slept the whole afternoon and night.
Today
He woke up a couple of times in the night and I got up with him at 4am, but all he wanted to do was flop and cuddle and wouldn't eat any breakfast. I could tell he couldn't stay awake and he was nodding off. I kept trying to tempt him with different food but he was really shaking his head and going "no" to even treat-type food. He fell asleep at 9am so again I put him in bed. When I heard him rousing at 2pm (he was asking for more milk) I got him up to give him a wash, brush his teeth and change his clothes. I was really worried that he hadn't eaten in 24 hours so I sat him on my lap and spoon fed him some soup and soldiers. I got up to wash up and he fell asleep at the table! I tried to get him interested in his toys but he lay down on the rug and went back to sleep. I could tell he was hot again so took his temperature, he was 38.1. Eventually I let him lie on the sofa and watch telly for a while, he dozed in and out. Near bed time I gave him some Calpol and made him some scrambled egg, but he took one look at it and threw up most of the soup he ate earlier. I gave him a quick shower and put him to bed again with water in a little sports bottle, he has been flat out since. My DP came back from work just as he was coming out of the shower and tried to play peepo with him under his towel, DS was smiling and playing along, holding the towel over his face about to pull it down to peepo but then suddenly fell asleep under the towel. 
I am really worried that he was sick when his problem was so clearly respiratory before, could he have a virus that is spreading? I am taking him to the doctors tomorrow definitely (unless he wakes up with a dramatic improvement) but I am worried that it could be something like meningitis and that maybe I should contact out of hours or take him to the hospital? My DP thinks he just needs to sleep it off. I do have a habit of Googling things and getting a bit paranoid. He is sleeping soundly right now so part of me thinks he might have a point, the other part is thinking 'what if'.
Sorry if this is rambly, I am tired and worried.