With the chill of winter now frosting local lawns, people are cranking up their home heaters to warm the crisp air inside.
But take caution, warns a Merced doctor, a nurse and a resident who shared stories of carbon monoxide poisoning.
If a home heater is working properly and has the appropriate ventilation, there should be no problem, said Dr. Barbara Showalter, who runs a private family practice in Merced. Unfortunately, it can often be hard to detect when there is a problem.
Carbon monoxide is a dangerous gas you can't smell or see, according to Pacific Gas and Electric Co. If you breathe it in, it enters your bloodstream and robs blood cells of oxygen.
Most fuel-burning equipment -- using natural gas, gasoline, propane, fuel oil and wood -- produces little carbon monoxide if it's installed and maintained right. If there's a shortage of oxygen to the burner, or venting isn't adequate, the gas can increase to dangerous levels, PG&E stated.
The company suggests installing a carbon monoxide detector and alarm, as well as regularly inspecting heating system vents and chimney flues.
Rita Haynes, 58, said she still suffers from shortness of breath after years of unknowingly inhaling the gas caused by a heating/air conditioning unit's blocked vent.
She bought her dream home in Catheys Valley in 2003, and workers came out to replace its roof shingles in 2005, said Haynes, a critical care nurse at Mercy Medical Center Merced. The following winter, she began to feel nauseous and dizzy and displayed flulike symptoms. "I even slipped on my stairs -- my legs were like rubber," she recalled. "I've never been so weak in my life."
Her symptoms continued off and on, and the usually healthy nurse was confused as to why.
In early 2007, her homebuilder discovered that the roofers in 2005 had accidentally detached air vents coming from the heating/air conditioning unit. Haynes said this caused carbon monoxide to spill into the attic for more than 10 months before she discovered and fixed the problem.
She's still not feeling 100 percent. "I never thought this could happen," she said. "I'm a healthy person."
This was an example of chronic carbon monoxide poisoning, when someone is exposed to low levels of the gas over a long period of time, Showalter said. Symptoms include shortness of breath, nausea, fatigue, headaches or dizziness.
Doctors often point to the flu or food poisoning as the cause. "There isn't any symptom that would make you think of (carbon monoxide)," she said. "We don't have a good way to check medically."
A warning sign could be that everyone feels ill inside the house, but feels better when they leave. Showalter suggests people add carbon monoxide detectors to their homes to eliminate the guesswork.
The doctor leads a chronic pain and illness support group in Merced, where she met Atwater resident Julie Estes.
About 10 years ago, Estes, 48, went through a series of what seemed to be unfortunate events caused by her neighbors. But she later found out from a PG&E worker that these damaging incidents could have saved her from more serious carbon monoxide poisoning. "It was one of those freaky-deaky things," she said.
She allowed her neighbor's dog to stay in her house, but the animal got upset, destroyed her front room and may have broken a window. "We were in shock," she said. "The dog had never done anything like that before."
Estes and her children weren't sure why the window was broken, but assumed the dog had something to do with it. They waited for their neighbors to pay for the damage.
Soon after that, the same neighbor accidentally backed her car into Estes' home, putting a hole in the wall near the broken window.
During this drama, Estes dealt with her children's and her own recurring health problems. They had flulike symptoms, and her daughter developed asthma.
She also began to notice an odd burning-hair odor. This smell and all the damage to her home caused her to call out a PG&E worker to look for problems. He found that a missing chimney cap on her wall heater sent aldehydes -- causing the smell -- and carbon monoxide into her home. "He said the inside of the heater was filled with black soot," she said. "He said, 'Y'all should be dead.' He said, 'You don't have the flu -- you have carbon monoxide poisoning.' "
That's probably why the dog went wild trying to get out, Estes speculated. And the holes in her window and house, offering more ventilation than usual, probably saved her family from worse poisoning.
If you suspect carbon monoxide, turn off the suspected gas appliance as soon as it's safe to do so. Then open the windows to ventilate the area, PG&E suggests. Get out of the building, and make sure no one goes back in until you are sure it's safe.
Seek medical attention if anyone experiences symptoms after possible inhalation of the gas.
In the words of the old TV seat belt commercial, the life you save may be your own.
Reporter Dhyana Levey can be reached at 209 385-2472 firstname.lastname@example.org.