Seems to be so, at least for me.
For the last two days, I have had a fever over 102 degree F (don't ask me how much that is in Celcius...).
I have felt just horrible, with many muscle aches and chest pains.
Today, though, I mustered up the strength to play CoD4 on my 360.
Within minutes of playing online, I was pissed. A guy was hacking, and essentially flying around the map killing people.
But then I realized that I felt totally fine, that my fever had gone away. I was roasting and sweating, but hell, at least the damned fever was gone.
Then I stopped playing, and 30 minutes later, BAM! I had a fever again, body aches and all...
So, I went back to my 360 and continued to pwn noobs in CoD4, and I was fine again.
Thought this might be helpful during cold/flu season. xD