Japan has seen a series of incidents in which people inside cars stalled by heavy snow suffered carbon monoxide poisoning.

In these cases, exhaust gas flowed inside the vehicles after snow blocked their mufflers. The cases include the deaths of three men in Fukui Prefecture in February 2018.

Experts are calling on people to avoid nonessential use of vehicles during heavy snow and to remove snow regularly around vehicles’ mufflers.

Exhaust gas contains carbon monoxide, which causes headaches and impaired consciousness due to oxygen starvation from inhaling the gas.

People go into critical condition in one to two hours of carbon monoxide entering inside vehicles and in the worst case die. But it is difficult to detect the gas as it is colorless and odorless.

When mufflers are blocked by snow, exhaust gas that has nowhere to go fills up the bottom of vehicles. The gas then enters the inside of the vehicles through spaces such as air conditioner vents.

“Choosing not to drive vehicles when heavy snow is expected is an important choice,” an official at the Japan Automobile Federation said.

The official recommended that people always store blankets, emergency food, a shovel to dig snow and other items inside vehicles so that they can wait inside while the engine is off when their cars are stalled.

The official also said that even if people face an unexpected situation inside cars, they should take various measures, including checking to see whether the car door on the opposite side opens, and wait calmly for help while keeping warm.Speech