As Texans try to keep warm indoors, they may risk carbon monoxide poisoning, often without realizing the dangers, warned officials at the Texas Department of Health (TDH). Invisible, odorless and tasteless, carbon monoxide (CO) is a highly poisonous gas produced by burning fuel such as gasoline, natural gas, kerosene, charcoal or wood. Inside a home, CO can come from a gas-fueled furnace, water heater, clothes dryer, space heater, range or kerosene heater, fireplace or wood stove. At low concentrations, CO causes fatigue in healthy people and chest pain for those with heart disease. At higher concentrations, however, CO inhalation causes impaired vision and coordination, headaches, dizziness, confusion, nausea and death. Without good ventilation during use of fuel-burning appliances, carbon monoxide levels rise and, when breathed in, replace oxygen in the bloodstream. The more CO in the air and the longer a person is exposed, the greater the risk of illness or death. “With any combustion source, there is a risk,” said Kay Soper, TDH indoor air quality specialist. Dangerous CO problems arise when home appliances are poorly maintained or used incorrectly. Non-vented gas and kerosene appliances have the greatest potential to produce dangerous levels of CO in the home, according to Soper. In addition to these, smoldering or poorly vented fireplaces, slow burning fuels such as charcoal and vehicle exhausts also are potentially hazardous. New homes, or newly remodeled homes, have higher risks for carbon monoxide hazard because often they are sealed tighter than older homes. TDH offers these precautions to help prevent CO poisoning: ‘ Be sure all appliances are installed and used according to the manufacturer’s instructions. ‘ Have the heating system inspected annually. ‘ Have ventilation systems, including chimneys, flues and vents, checked every year. ‘ Don’t burn charcoal inside a house, garage, vehicle, or tent’not even in a fireplace. ‘ Don’t use an unvented gas or kerosene heater in enclosed spaces, especially sleeping areas. ‘ Never leave an automobile running in a closed garage or in a garage attached to the house even with the garage door open. ‘ Don’t leave the rear window or tailgate of a vehicle open while driving. Carbon monoxide from the exhaust can be pulled inside the car, van or camper. One key to safety, Soper said, is to examine the color of a flame. A hot blue flame produces less carbon monoxide and more heat than a flickering yellow flame. A yellow flame in the furnace or stove burner is a signal to have the equipment re-adjusted to get more air to it. Not only will the stove or furnace be safer, but it also should be less costly to operate. Soper said people with gas appliances should invest in a carbon monoxide detector. Widely available, CO detectors can warn people if carbon monoxide levels become high. Anyone who suspects symptoms of CO poisoning should open doors and windows, turn off gas appliances and go outside. In cases of severe CO poisoning, call the 9-1-1 emergency services.