I think the weed is a good immune system booster or something. I didn't start smoking weed until about 4 years ago. The only time I've been ill (fever) in the last 4 years was when I moved to boston and went without weed for several months.
Before weed, I used to sick at least once a year with a fever or bronchitis, strep throat, tonsilitus, etc. At least once a year and that was when I never smoked weed.
I've never been sick when I smoke weed daily, not once. A common cold sometimes but it usually clears up within a day or 2 and never had a fever or anything like that.
There's something to it man...