| When you pack, the last thing you might plan for is a gas you can’t see. But carrying a carbon monoxide alarm should be top of mind, experts say. Carbon monoxide, also known as CO for its carbon and oxygen elements, lacks taste, odor, and color and is produced by burning fuel. Left unchecked, a carbon monoxide leak could be lethal. It can pour out from faulty pool heaters or seep from a boiler in the basement. When the gas enters a room, there is no clear sign of trouble. “There’s no way to visualize that,” Kris Hauschildt, the daughter of carbon monoxide poisoning victims and founder of the prevention advocacy nonprofit Jenkins Foundation, says. CO poisoning symptoms aren’t unusual; headaches, nausea and dizziness could be caused by any number of common illnesses. Only an alarm can pin the cause to carbon monoxide. Unlike smoke alarms, CO detectors are not required by federal law in every room you’ll be staying in. Only 14 states require them in hotels and motels. It’s a silent killer with sizable impact. More than 400 Americans die annually from carbon monoxide poisoning not linked to fires, according to the Centers for Disease Control and Prevention, and more than 14,000 are hospitalized. Safety experts say those are underestimates. Cases are hard to track and get referred to different federal agencies depending on where they occurred. And no government authority tracks incidents in the hospitality industry. “Carbon monoxide does not live under one branch of the federal government,” Hauschildt says. Earlier this month, a La Quinta in Jacksonville, Texas, was evacuated after multiple people reported trouble breathing and passing out; a mother and her 2-year-old were taken to the hospital. A defective heater was to blame. In March, Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner, died at a beach resort in Costa Rica from a carbon monoxide leak. In February, three women died in their hotel room in Belize from CO poisoning. While tragedies can raise awareness of CO dangers, it’s not top of mind for many travelers. “Many people just don’t think about it,” says Neil Hampson, a retired physician who’s published numerous papers on carbon monoxide poisoning and prevention. When people are aware of the risk, he says, they often buy a portable carbon monoxide detector for themselves, then tout it to friends and family. Often, there is no place to look at the maintenance history of a hotel before you decide to stay there. “All that information is private,” Kos Galatsis, founder and chief executive officer of air monitor technology firm Forensics Detectors, says. “The best one could do is look at reviews.” Portable CO detectors’ prices ranges from $30 to $100 and they generally fit in the palm of your hand. Galatsis says the key component of any alarm is the sensor. “It’s the eyes and the ears of the gas,” he says. The test button only checks the device’s mechanical functions, like the buzzer. To test your detector you have to expose it to carbon monoxide, he says. Run an experiment: Light a match stick, let it smolder and place it and your detector under an overturned cup or jug. The alarm should go off. — Rainier Harris | 
