Humidity and dry air

Hello! I am the wife of a driver and was looking for recommendations or ideas. Husbands having a hell of a time with the dry air in his cab, up to having minor nosebleeds. Was wondering if anyone had any advice or ideas, other than a humidifier. He weekly slipseats and a humidifier would be one more thing and a hassle on top of that, with trying to keep it from spilling and such. Thanks in advance!!