Answer:
Your body wouldn't fight off the infection as efficiently
Explanation:
[There is no multiple choice; I will answer with the best of my knowledge]
Other theories may be incorrect because if you did not run a fever when you got sick, you body fluids and functions would not have the ability (or strength) to fight off diseases, infections, etc. since it don't run a fever. It's pretty obvious to tell that this could do so since you are missing a piece (not running a fever).
--
Think of this as a missing piece of a puzzle, it isn't considered a completed puzzle unless it has all the pieces.
--
Source:
BrainPop