1) Let's get the smoking belt or impeller won't engage examples (usually related) first. You grab the auger engagement handle no snow comes straight from the chute but the belt will start squealing or smoking. Release that handle RIGHT NOW and shut down your snow blower. Tip it back on it's handle bars if possible. If the gas tank is full, put some plastic from a grocery bag under the filler cap to keep the gas from pissing out of your cap vent. Reach in oh no- the second stage impeller. That's the 3 or 4 bladed fan that throws the snow straight from the chute on a two stage snow blower. See if you possibly can turn it by hand. If not, it may be frozen to the bottom with the drum it is stored in. There is usually a drain hole in the bottoom of the drum to avoid this but it is not always sufficient. Occasionally the impeller blade coasts for a stop with one of many blades straight down. This can make it easier to freeze.
2) Ways to repair: Drag or drive your snow blower into an area and turn on some warm to thaw out your snow blower. If people don't have this luxurious, use a hair dryer. I've also seen people make a tent with a tarp on the snow blower and which has a space heater to thaw out the device. Be careful how close you setup the heater and this direction you point that. A space heater can melt or start a plastic tarp on terminate. You could just direct the place heater into the auger area and hope for the best. It doesn't usually take an excessive amount to melt the winter snow storms. Using a propane torch could be the least desirable and the majority of unsafe option, as a great open flame is serious near any outdoor power equipment. Just a little bit of gas spilled nearby can be a potential disaster waiting to occur. You've read about it inside newspaper so don't quite possibly go there or you'll end up in the newspaper too. I can't explain how many times, back in the flooring buisingess, when we just dragged a lot of frozen snow blowers inside our warm shop in advance of entering the "triage unit" which was all that was needed to cure the problem.
3) How to prevent: Clean the snow heli-copter flight snow blower and within the impeller /auger housing when done snow blowing. It should be fairly obvious in the event the starter is removed where the "dog" or metal tab that engages into the starter cup is situated. You shouldn't have to remove the pulley but it's best to remove the center screw so the lube gets down in the pivot area. In that case, any sort of grease is usually NOT recommended. Use WD40 or even similar liquid lubricant. Grease just gets gummy in winter, especially on a smaller gadget like the starter dog.