You can buy an inexpensive humidifier that makes warm steam for about $15-$20 at a drug store. They are the kind that you add a pinch or two of salt. When the water runs out, the thing stops working (until refilled), so it does not waste electricity.
I think it’s worth buying because they come in handy rather often. I find using a humidifier helpful during the winter even without having a cold.
I think doctor’s don’t recommend warm humidifiers any more… (safety issues) – only the cool-mist ones. Which aren’t that expensive either… and work equally well.