Best to vaporize, if you can. The smoke really won't help your lungs get better. As StormCrow said, it'll be great for the appetite and aches, but it won't help you get better any quicker. There seems to be conflicting information among the scientific community as to whether it damages your immume system, does nothing, and in a few rare reports actually helps. I can tell you from personal experience, though, that toking has never made a cold worse for me.

I'd suggest having a toke (preferrably a vape), and a nice hot bath. Nothing feels quite so good as a hot bath when you're sick. Also, try taking a Vitamin-E capsul then taking 6-8 grams (6,000-8,000mg) of vitamin-C, spread throughout the day. VC kicks a virus's ass, but only at such doses as I described. Don't worry, it's about as remarkably non-toxic as THC, you don't have to worry about hurting yourself from too much till you start taking it in the hundreds of grams (though i wouldn't recommend it as it would interferre with normal oxidative processes at those kinds of doses..... though that's also a biology issue still under heavy debate).