This Portable Travel Essential Could Save Your Life. And It Costs Less Than $35.

If you’ll be sleeping in a hotel, consider packing a carbon monoxide detector. That’s true whether your lodging is out of the country or stateside. Although you may have seen widespread media reports about international incidents of CO-related deaths in lodging, poisonings are also a serious issue in the United States.

Kris Hauschildt, founder of the Jenkins Foundation, a nonprofit dedicated to the prevention of CO-related deaths and injuries, lost both her parents to carbon monoxide poisoning at a hotel in North Carolina. The media didn’t report their deaths until a boy staying in the same room died of the same cause two months later, Hauschildt told me in a video interview.

Even though carbon monoxide poisoning is a leading cause of poison-related deaths in the US, resulting in over 14,000 non-fire-related hospitalizations and at least 430 deaths annually, there are shockingly few laws requiring CO detectors in public buildings, including hotels, motels, and resorts. The New York Times previously reported that the lodging industry has lobbied against updates to the International Fire Code in the past.

Only 14 states have statutes that mandate carbon monoxide detectors in short-term lodging, which includes hotels and resorts. Even those statutes are not always comprehensive. Some require detectors only in new buildings or in guest rooms containing or adjacent to fuel-burning appliances, though Hauschildt has found many examples of CO leaks in nonadjacent hotel rooms, with the gas reaching them through the ductwork.

Part of the issue with assessing the prevalence of CO incidents in lodging is that there is no federal agency that specifically tracks it. And deaths in vacation rentals aren’t tracked, either. The sites of rental platforms such as Airbnb and Vrbo allow you to search for rentals with CO alarms installed, but there’s no guarantee that those alarms will be working when you arrive. Alarms made before 2010 may not have end-of-life signals, which is why it’s important to check that detectors, including those in your home, are in working order.

Focusing too heavily on the symptoms of carbon monoxide poisoning may give people a false sense that they’ll know if they’re suffering from CO poisoning.

That’s because common symptoms of CO poisoning — such as headache, dizziness, fatigue, and nausea — resemble the signs of other illnesses, especially those that are easy to come down with while you’re traveling. You might think you have food poisoning, the flu, COVID-19, or a migraine, or that you simply had too much to drink. “If you have a headache, you’re not going to call the fire department,” Hauschildt noted.

On top of that, if you’ve ever gotten sick on vacation, you’ve probably done exactly what I’ve done: You’ve stayed in your room. If you have carbon monoxide poisoning however, this will only make you sicker, and the sicker you get, the less likely you are to get out, since another effect of CO poisoning is disorientation or confusion.

And many CO-related deaths happen while a person is sleeping, so some people might experience no symptoms at all.

All of that is to say: A detector may be the only way for you to know if you have carbon monoxide poisoning.

Luckily, CO devices are compact, readily available to buy, and relatively inexpensive. Unlike smoke alarms, carbon monoxide alarms don’t need to be mounted because CO is about the same weight as air; as a result, many residential detectors for sale today are plug-in devices that also have a battery backup. These are totally suitable for travel as long as they conform to the UL 2034 standard, which reflects the latest safety regulations for such devices. Packing your home’s plug-in alarms to take on vacation can be especially useful if you’d like to have several for coverage of a larger rental.

But it may be worthwhile to get a dedicated, portable, battery-operated CO alarm that you can store with your travel supplies and that you won’t have to remember to pack or return to its original location.

Doug Mahoney, who writes Wirecutter’s guide to smoke alarms, suggests the First Alert CO710 Carbon Monoxide Detector, a battery-operated detector that is about the width of two iPhones and weighs less than half a pound. It can slip into the front pocket of a carry-on.

Although we haven’t extensively tested CO detectors as their own category, we have tested combination fire alarms and CO detectors, and Doug is confident in this recommendation.

Currently, only two well-established manufacturers of residential smoke alarms, First Alert and Kidde, undergo rigorous third-party testing to confirm that their products comply with UL standards, as indicated by a UL or Intertek mark on the back of the device. “This certification is a pass/fail test for us,” Doug told me. “If a company has it, we consider their products. If a company does not have it, we will not consider their products.”

Unfortunately, Kidde’s track record with its products is “disturbing,” according to Doug, owing to a perpetual history of large-scale recalls. That makes First Alert the last one standing.

We also think First Alert devices are nicely built and easy to use. For travel, the battery-operated CO detector has an advantage over a plug-in model: Not only is it smaller and able to work without occupying a precious outlet, but also, if you’re vacationing internationally, you won’t have to deal with a travel adapter for it. You can also place it at eye level so that you don’t forget to pack it when you leave. Plus, the lithium battery should last about 10 years. Just note that because of that battery, you may want to slip the detector into your carry-on or personal item instead of your checked bag.

Unless the detector is issuing an alert (or you’re running a test), the display simply shows the temperature, a pleasant feature I like. It lets you forget about the risk of carbon monoxide poisoning while keeping you protected.

If you’re in a hotel room, you can just place the detector on a nightstand. If you’re renting an entire house, the Environmental Protection Agency advises putting a detector on every floor. (Some sources go further, recommending detectors on every floor and in every bedroom.) Doug also suggests placing one in the basement, though not directly next to a furnace or any fuel-burning appliance, such as a hot water heater, which could cause a false alarm. If you have only one detector, the EPA suggests placing it near sleeping areas and confirming that it’s loud enough to wake you.

If your carbon monoxide detector merely chirps, it may be malfunctioning or in need of a new battery. But if it goes off continuously, get outside to fresh air as quickly as possible (or open windows if not) and then call 911.

Carbon monoxide poisoning is a risk pretty much anywhere you sleep overnight, so consider bringing a detector if you’re staying on a boat with a cabin, in an RV, or even in a tent.

The BoatUS Foundation for Boating Safety and Clean Water recommends using a carbon monoxide detector in any sleeping quarters on a boat — especially since the symptoms of CO poisoning can resemble seasickness.

If you own a boat, consider a CO detector that’s specifically designed for marine use and is UL 2034–compliant. Marine detectors are made to stand up to the harsh boating environment and have more comprehensive testing requirements, which involve considerations for powering up the boat and more. Common makers of such models include Fireboy-Xintex and Safe-T-Alert, though we haven’t tested them.

Be aware that poisoning can happen when you’re on the deck of a boat or swimming near the exhaust of an idling or nearby boat. Children are particularly susceptible and have died after a day out on the water.

RVs also have specific alarms that meet more comprehensive testing requirements tailored to that type of vehicle. RV exhaust (including from RV neighbors), gas barbecues, fuel-burning equipment, and gas generators can all lead to CO poisoning in RVs. Again, only newer alarms have end-of-life signals, so if you’re staying on a boat or in an RV that already has a CO alarm, double-check that it’s working.

While UL recommends always getting marine- or RV-specific alarms when staying in those environments, some boating-safety experts I spoke with suggested that if you’re staying just a night or two, bringing a residential-grade detector is better than nothing if the sleeping quarters don’t already have a working detector.

You should also be aware of the risks of CO poisoning while camping. People have died due to using fuel-burning camping equipment, such as charcoal grills, stoves, and some lanterns. Avoid using that kind of equipment inside tents in all circumstances. Generators are also a common cause of CO poisoning — killing some 70 people in the US each year, according to the CPSC — and should be used only outdoors, in well-ventilated areas.

If you frequently travel by car, consider reading up on the main causes of vehicle-related CO poisoning, especially if your car uses a keyless ignition.

There are few laws in the US that require carbon monoxide detectors in short-term lodging, which includes hotels, motels, and vacation rentals. And you’re unlikely to know if you’re being poisoned, since the symptoms resemble those of common illnesses.

Even if a hotel or vacation rental says it has carbon monoxide detectors, you should check that they actually work, especially since older detectors don’t always have end-of-life signals, and consider bringing a detector anyway, just in case. You should also be aware of the potential sources of carbon monoxide in other travel-related situations, such as while you’re boating, camping, or RV-ing.

Luckily, in most cases carbon monoxide poisoning is entirely preventable. A simple, lightweight, battery-operated CO alarm is easy to take with you, should last about 10 years, and costs less than $35. It could save your life.

This article was edited by Katie Okamoto and Hannah Rimm.