I bought this item for my son when he had a cold last year.  I had the unit on for about 2 hours when I noticed he was doing alot of coughing and complained that his asthma was bothering him.  Within another hour my asthma started bothering me and I started having chest pains.  I new right then it was the unit.  I  unplugged it and opened the windows and it took about 8 hours for my son and I to feel better. … read full review »