Humid air feels warmer than dry air. Increasing the humidity of your home also helps you resist winter colds and moisturizes dry skin. Operating a room humidifier will make you feel more comfortable. If your heating system has a humidifier, make sure that itâ€™s functioning properly. You can also add humidity by keeping house plants. Plants clean the air and add moisture to it at the same time. Putting trays of water on top of radiators also helps. So does leaving the bathroom door open after a shower, to let that warm steamy air circulate through the house.