Sometimes the stories we tell ourselves have a way of misleading us. One belief is that heavy consumption of holiday turkey results in drowsiness, attributed to high levels of tryptophan contained in the meat.

What's probably making you sleepy after Thanksgiving dinner is any combination of alcohol, relatives retelling the same old tales as if they were sagas, and a carbohydrate-heavy meal, but not the turkey itself. Another possible contributing factor is carbon monoxide (CO) exposure.

Thanksgiving is the start of the holiday and heating season in Lake County. We fill our houses, cabins and modular homes with relatives and friends, and then fire up our oven and stove.

Perhaps the wood burning fireplace insert and older furnace are blazing at opposite ends of the house. After a long drive, one of your guests is refreshing themselves in the shower that is fed by a propane water heater. If they are running, the bathroom and kitchen fans plus the clothes dryer are also exhausting air from the living space.

All of these combustion appliances and fans are competing with your guests for available oxygen. This situation is the perfect storm that can result in back drafting of combustion fumes into the living space instead of going up the flue. Only a few of the above mentioned combustion conditions are needed for back drafting to occur.

These appliances burn fuels, typically gas, both natural and liquefied petroleum, kerosene and wood. Under certain conditions, these appliances can produce deadly CO. However, with proper installation and maintenance, they are safe to use.

CO is a colorless, odorless gas produced by burning any fuel without enough oxygen. The initial symptoms of CO poisoning are similar to flu, and include drowsiness, headache, fatigue, shortness of breath, nausea and dizziness.

Building scientists have thousands of anecdotal examples of people getting “sick” when exposed to low levels of CO; frequently, “the flu” is falsely blamed. Exposure to high levels of CO can cause death.

“Each year, CO poisoning associated with using fuel-burning appliances kills about 200 people,” said Consumer Product Safety Commission Chairman Ann Brown.

An annual inspection and service is the first line of defense against this silent killer. Having a CO alarm is another simple and effective precaution.

A timely suggestion for the holidays: Yes, it makes clean up easier, but covering the bottom of ovens with aluminum foil is dangerous. Doing so blocks the combustion air flow through the appliance and can produce more CO. So forget the foil and bring out the scrubbies after your guests depart.

“The secret of energy efficiency is that there is no silver bullet; but there are a thousand silver bb’s.”

Jim Tanner is a Cobb resident who is always interested in learning about new and old silver bb’s for finding shelter and comfort from the elements.