Losing HVAC when I am sick

I’ve been feeling pretty sick lately and I’m not sure what’s wrong with me. .I’m starting to wonder if I don’t have some strain of the flu or something. My stomach hurts and I have had a headache for several days now. I feel like  I’m going to throw up, too. I have chills and I’m cold, even though it feels like my temperature is on the rise. I can’t seem to get warm, no matter what I do. I have turned up the temperature on my thermostat so that the heat comes on, but I’m starting to think that there’s something wrong with my oil furnace. I don’t know because I feel too sick to venture down the stairs to the basement to check on the oil furnace! I feel like my legs are too wobbly to make it down all of those stairs. I’m just curled up on my bed, shivering and feeling like I have the air conditioning blasting on my face through the air vents instead of the heating system going at full blast through the heating ducts! My husband is out of town. When I talked to him last night he said that he doesn’t  think that there’s anything wrong with our HVAC system. Apparently, he had the local HVAC contractor out to the apartment to do routine HVAC service a few weeks ago. So he’s convinced that the HVAC system is fine and that there’s just something wrong with me. He told me to get my butt to the doctor in the morning to see what in the world is going on with me. He doesn’t think the gas furnace is broken but he does think that I have a fever or some kind of infection going on.