Tommy, the rat...with a fever!

Question
Hello Debbie, a few days ago my rat Tommy (20 months-old male) started to feel quite feverish! He's pretty hot to the touch and sweaty (fur feels a little damp on his sides) but surprisingly he has icy-cold feet! otherwise seems alright (being a very lazy rat as he it's difficult to say if he's taking less of his free-ranging exercises)...eats as usual, is not hunched or sneezing... with no discharge...no diarrhoea...and no visible signs of pain...the only other concern is a couple of days ago I found a small lump (the size of a peanut?) just under his ribcage- it feels soft...quite frankly, it could be just a bit of fat (well, Tommy is our "Big Belly" xi)...only it feels slightly different than the fat around it...and even if his appetite is still very good, he seems to loose some weight around his lower back/ hind legs (the skin in that area looks definitely more "sagged").
Because of the Christmas and New year's craze all the vets here have been closed- I can make an appointment on Monday, so possibly see the vet next week...that's still 5-6 days to go! Can you help me? Is there anything I can do to alleviate his fever? (I put extra 3 cotton shirt rags onto his hammock to keep his warm- also keeping a comfortable temperature +18 degrees celsius in their room, added some fresh spinach leaves and fresh apples to his diet to prevent dehydration).
Thank you for a quick response!

Answer
Hi Jana,
Rats normally have a warmer body temperature than humans, so it is normal for them to feel warm. And rats don't sweat. And it is normal for their feet to feel quite cool. The only way to tell for sure if a rat has a fever is to take their temperature rectally. Chances are he is fine.
Deb