NEW YORK (Reuters Health) — Carbon monoxide poisonings at hotels and motels may not be common, but they’re not becoming rarer with time either, according to a new study.Using databases of news reports and court cases, researchers were able to document 68 incidents of carbon monoxide poisoning at U.S. hotels, motels and resorts between 1989 and 2004.

The incidents sickened 772 people, 27 of whom died, the researchers report in the American Journal of Preventive Medicine.

Based on these figures, the odds of any one person suffering carbon monoxide poisoning at a hotel are quite low, said lead study author Dr. Lindell Weaver of LDS Hospital in Salt Lake City, Utah.

However, he told Reuters Health, “when it happens, it can be serious and lethal.”

Carbon monoxide is a colourless, odourless gas found in combustion fumes, such as those from cars, gas ranges and heating systems. Carbon monoxide can build up indoors if a furnace, water heater or other fuel-burning appliance is in poor condition or not properly vented.

Some symptoms of carbon monoxide poisoning include dizziness, nausea, chest pain and confusion. Exposure is particularly dangerous when people are asleep, since the gas may prove fatal before they awake.

In the US, federal law requires hotels, motels and resorts to have smoke detectors in every guest room, but there are no national laws regarding carbon monoxide detectors.