Question: why do i get a headache when i sleep with the heater on?
Answer: Headaches—You can suffer from migraines and sinus headaches due to clogged sinuses and smells from mold, fungus, and dust. You may also suffer from headaches due to carbon monoxide from faulty furnaces. Watery/itchy eyes—You can have dry, watery eyes from too much dust and dry air.