Air quality in home?

I highly doubt your using any kind of gas heat this time of year. So I'd rule out Carbon Monoxide. The only other thing that may cause that would be a gas water heater, highly doubtful.

Sounds like you got a bad case of toxic mold somewhere in the house. Could be inside the walls and not visible. Toxic mold creates these same symptoms you're describing.

Have you had ANY kind of water leaks/damage lately? Leaking pipe, roof, flood, leaking dishwasher, leaking water line to ice maker?

Call a professional to come out and test an air sample. It's nothing to mess around with.

I agree with Jethro. You and your husband's symptoms sound very

much like carbon monoxide poisoning. I think you could possibly

check with your local fire department. They may have air quality

testers and would probably check the air in your home at no charge.

Do you experience headaches at all? That can be another symptom

of CO2 poisoning. I would get this checked out sooner rather than

later. CO2 can kill.

You can have a company test the air in your house. Also that sounds like carbon monoxide poison. Are the dogs sleepy and fatigued too ??? Might get it checked or you can buy carbon monoxide detector at your favorite home center.

Whoa! That sounds dangerously like carbon monoxide poisoning! Call your gas company or even your local Fire Dept (not through 911!) and see if they can test it for free.

It sounds to me as though you both have some of the symptoms of exposure to mold. You should not only call someone to inspect the house but possibly go to a doctor that can do a simple test on the two of you to determine whether you are exposed to mold.