Gerulaitis’s death drew attention to a normally low-profile household poison. In 1991, the last year for which figures are available, the death toll from unintentional carbon-monoxide poisoning was 594, according to the National Center for Health Statistics. Although the number of victims has been steadily declining in the last decade, health officials worry because carbon-monoxide poisoning is becoming increasingly hard to detect. Defective furnaces, flues and oil heaters have always been potential hazards because of leaks or clogs. But in the past, impurities in fuel gave off a scent or left soot that could signal a problem. Today’s purer fuels often leave no trace. And modern houses are also better insulated–good for saving energy, bad for letting in air that might dilute the poison.

In its initial stages, carbon-monoxide poisoning is difficult to spot because the symptoms–headaches, fatigue, nausea and dizziness–mimic those of the flu. Carbon monoxide kills by limiting the body’s ability to use oxygen. Normally, oxygen passes through the lungs and then enters the bloodstream, where it bonds to a protein molecule called hemoglobin. Hemoglobin carries oxygen to the muscles and organs. But carbon monoxide binds to hemoglobin 300 times as well as oxygen does, blocking the sites where oxygen would ordinarily land. As the percentage of carbon monoxide in the body increases, the victim succumbs to a slow, velvety suffocation.

In the wake of Gerulaitis’s death, stock prices of First Alert, which sells carbon-monoxide detectors, rose dramatically. There are actually three types of home detectors on the market. One uses a chemical that changes color in the presence of carbon monoxide. A second type uses a piece of metal that is heated by being plugged into an electrical outlet; the metal reacts with carbon monoxide. Both sound an alarm. Another type is a card with a dot that changes color when it senses carbon monoxide–which, Consumer Reports points out, isn’t much help if you’re sleeping. Experts recommend placing alarms near bedrooms.

The tragedy of Gerulaitis’s death is that carbon-monoxide poisoning is preventable. Southampton Village’s building inspector, John Foster, said that the cottage where Gerulaitis was staying was not certified for occupancy as living quarters. An inspection could have uncovered a ventilation problem.

At Gerulaitis’s funeral, his friends remembered him as a generous man who enjoyed life. “Forty years was not long enough for Vitas to live, but it was enough to leave a lasting impression on all of us,” his friend Jimmy Connors told mourners in a eulogy. “I loved him and I’ll miss him.”

Carbon monoxide is a leading cause of unintentional poisoning deaths. Annual checks of major appliances can prevent such accidents. A guide to potential hazards:

Grill operating in an enclosed area Gas dryer blocked vent Portable heater blocked vent Gas refrigerator blocked vent Water heater corroded or disconnected vent Gas or wood-burning fireplace improper ventilation Furnace cracked heat exchanger, leaking chimney pipe or flue Gas stove improperly installed gas range or cooktop vent Chimney clogged or blocked opening Automobile exhaust fumes from attached garage

Carbon monoxide is a colorless, odorless, highly poisonous gas that is produced whenever a fuel is burned without enough oxygen available.

Motor vehicle 43,536 Falls 12,662 Drowning 4,621 Carbon-monoxide 594 poisoning

(SOURCE: NATIONAL CENTER FOR HEALTH STATISTICS, FIRST ALERT, CENTERS FOR DISEASE CONTROL AND PREVENTION)