Humidification to reduce respiratory illnesses in nursery school children.
D000041:Absenteeism; D000391:Air Microbiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006361:Heating; D006801:Humans; D006813:Humidity; D008297:Male; D012141:Respiratory Tract Infections / Q000517:prevention & control*; D012578:Schools, Nursery