I'm really feeling quite clueless because my son is 14 months old and it's the first time he's been unwell.
Yesterday he was very 'easily upset' and wouldn't stop crying at one point. That all changed come 7pm (the unwell thing started at about 4.30pm). He went to sleep.
He woke up at about 11pm last night, he could've easily gone back to sleep but he was boiling hot! I brought him down to watch the rest of the film with me and DH. He just lay in my arms silently watching the film... I found it really strange. He's extremely lively and he's never just sat and watched something before. I gave calpol and we went to bed.
I woke him again at 5am because he was absolutely boiling again. He's just woken again now and still, temp hasn't changed. Boiling again and in my arms half asleep, fading into the distance with his eyes. It's horrible to see.
When do you start to panic and act on these sort of symptoms? I really don't know 
His feet are a lot cooler than the rest of him and have been since last night, but by no means stone cold.
I've checked for a suspicious looking rash and there isn't one, just a bit of what I think could be skin change looks wise because of how hot he is.