It can be done, but is it worth the risk?
Many of us, me included, feel a psychologically need to exercise that can often lead us to make poor decisions regarding our health.
I try my hardest to tell myself that it's ok to take a break, but I get so anxious about it (which is crazy, since this is technically the "off season" anyway).
Case in point. last week I was fighting an upper respiratory "head cold". We had a break in the weather last week and I wasn't feeling great, but I thought I was feeling 'good enough'. Plus, I figured I could sweat it out. Unfortunately, my plan backfired and I'm only now starting to feel better.
Everybody is different, but I think for me as long as my cold is in my head and I work out inside (lightly) I'm usually ok.
I found some pretty good tips here.