Why isn’t my husband in bed?

I woke up at 4AM last night, and my husband wasn’t in bed.

I normally don’t worry about it if he is up early.

He had always been an early riser. I listen to hear if his computer or the television is on, and I go back to sleep. This morning I woke up, but I didn’t hear anything. I decided I had to get up and check on him. When I didn’t see him in the kitchen, I started looking through the house. I found him in the basement, talking to himself. He was staring at the furnace mumbling. I asked him if there was a problem. He told me the heating had stopped working about an hour earlier. He was trying to figure out what was wrong with the furnace. I told him I could call the HVAC company and see what time they could send someone out. He didn’t want to spend a lot of money on an emergency call so I was going to wait until 8AM to call. I suggested that he come back to bed and I could keep him warm. He laughed and said that he had a space heater on. He would be okay. I was a bit upset that he gave me that answer. I was shivering by now, so I went upstairs, curled up under the blankets and shivered until I went to sleep. I woke up two hours later. I made coffee and then I called the HVAC company. My husband came upstairs about then. He was going to make the call, because he couldn’t figure out what was wrong with the furnace. He also wanted to apologize for being so rude.

furnace filter