Take their temp once. After you know they have a fever then we know why they're acting "sick", because they are. Then stop checking their temp. There is not one bit of useful medical information that is gained by repeatedly checking the temp. As was said in another post, a virus typically has a higher fever than any bacterial infection anyway.
Then its all about Hydration, breathing, and mental status.
The temperature does not really play into the picture. Which is why I love the parents that didn't give their kid ibuprofen so I could "see the fever". Guess what? I don't even care about the fever!
Ignore that last paragraph. It's been a long winter.