Westerly, RI – By Ryan McBride, The Sun Staff – Julianne Cook said she had a headache, grew dizzy and vomited before an ambulance rushed her from her Pond Street home to The Westerly Hospital.

It may sound like Cook suffered from influenza; however, blood tests later found that the 57-year-old woman had carbon-monoxide poisoning.

Call carbon monoxide the silent, but deadly, gas.

Unintentional carbon-monoxide poisoning kills about 2,100 people in the U.S. every year, according to the Journal of the American Medical Association.

The U.S. Environmental Protection Agency reports that carbon monoxide is a colorless, odorless gas, which limits the ability of blood cells to carry oxygen.

Here, Westerly Fire Department Chief David A. Sayles said he has seen a growing number of carbon monoxide-related assistance calls to his station over the past few years. The gas emanates from fuel-burning appliances (furnaces, ovens, stoves and water heaters) and sources such as vehicle exhaust, blocked chimney flues and charcoal grills.

According to the federal Consumer Product Safety Commission, malfunctioning appliances contribute to about 200 deaths from carbon-monoxide poisoning every year.

Earlier this month, a hearing impaired woman from Hopkinton escaped possible death when her dog alerted her that a carbon-monoxide detector in her home had activated. In this case, local fire officials attributed the gas emissions to a leaky pipe connected to the furnace.

Local firefighters respond to the most calls during the winter months, when people seal their homes from the harsh elements and crank up the heat, Sayles said.

The department found “detectable” levels of carbon monoxide at 13 homes in 2003, and at 31 homes in 2004, according to fire reports. “So there is a significant increase,” Sayles noted.

He said that he attributes the spike in calls to modern construction of homes, which are highly insulated to make them “energy efficient.”

“We have had instances in Westerly where we’ve had high levels (of carbon monoxide in homes), and people were transported to the hospital,” he said.

Sayles’ advice to people wishing to avoid carbon-monoxide poisoning: install a detector.

In fact, Rhode Island General Law mandates that all dwellings must have carbon-monoxide detectors located on each floor and within 10 feet of every bedroom door. The law permits homes built prior to Jan. 1, 2002 to have plug-in type detectors, but homes after that date must have “hardwired” alarms mounted on ceilings.

But preventing carbon-monoxide poisoning doesn’t stop with installing a detector.

Sayles recommends that the detectors be checked every month, and that homeowners follow the manufacturer’s instructions charges.And during the winter months, people should open widows on a regular basis to keep their homes ventilated, he said.

“The colder it gets,” Sayles said, “the more frequent calls we get (for carbon monoxide).”

Every time the alarm activates, the chief said, people should act as if it is an real detection. People should evacuate their home immediately, leave an entrance open for ventilation and notify the fire department from a neighbor’s residence.

On Monday, Cook had returned home from the hospital. She said that she was still fatigued from the carbon monoxide that she inhaled the day before.

“This is such a dangerous thing,” Cook said, “I could have died and not even have known it.”