Hello there, Before bed last night I put on the electric heater for the first time this year. The heater started to smell like some thing was burning off of it like dust or some thing so I shut it off. When I woke up I had a sore throat, headache, runny nose, and a dry cough. My saliva was very thick and when I tried to cough up mucus there was not much but it was dark (almost black) and thick. My symptoms persisted through out the day. Is this some thing I should worry about? Thank you, Jeff