While people tend to think of drowning as a summer safety risk, more children and young adults are drowning now that winters are getting warmer, according to a new study.

The study, published in the journal PLOS One, looked at 4,000 drownings in 10 northern countries including Canada, the U.S., Finland, Sweden and Germany over the past 10 to 30 years.

The researchers found that winter air temperatures were closely linked to the number of drownings that happen each winter.

Specifically they observed that when temperature were between –10 oC (14 F) and –5 oC (23 F) the number of drownings went up significantly and as temperatures got closer to 0oC (32 F) they increased five fold.

But once temperatures went over 0oC drowning numbers drop – probably because the ice was visibly unsafe or non-existent.

“The time when the risk of drowning is greatest is at the beginning and the end of winter, which also corresponds to the weakest ice, when it is less stable and less thick,” explained lead researcher Associate Professor Sapna Sharma. 

As average winter temperatures rise due to climate change there might be more winter drownings as the ice is unsafe for greater periods of time and people are more likely to fall through.

“The climate is changing and it’s affecting when you can be on the ice safely. Individuals need to take that into account, especially this winter when more individuals will be out enjoying winter ice activities,” said Sharma. “Times have changed, and climate has changed. Winters are among the fastest warming season, especially in Northern countries, and we’re seeing the impacts of that on our lakes, and it’s also contributing to tragedies each winter.”

The researchers found that for some countries, the number of winter drownings through ice represented 15% to 50% of the total annual number of drownings.

Canada had the highest number of winter drownings and the territories, where people use frozen lakes more for their livelihood, such as hunting and fishing, had the highest number of drownings per capita in all of the regions analyzed in 10 countries. 

Previous research has also noted that while more people drown in the summer months, drownings in winters are more likely to be fatal.

One hospital in Dallas, Texas found that 7.8% of drownings were fatal during the colder months, whereas only 2% of drownings were fatal during the warmer months.

In fact, there’s evidence to suggests that 20% of people who fall into cold water will die within the first two minutes due to shock.

And if you do survive the initial plunge your chance of survival drops by the minute. Cold water dramatically impedes one ability to swim as body heat is lost 25 times faster in cold water than air and muscle begin to stop functioning after 10 minutes – depending on the temperature.

According to an article published in The Lancet, cold water immersion deaths represent the third most common cause of accidental death in adults, and the second in children, in most countries. 

“In this study, we also looked at who was drowning, when, and what kind of activities they were doing at the time,” said Sharma. “Almost 50 per cent of drowning victims are children less than nine years old playing on the ice, while the majority of victims drowning while in vehicles, such as snowmobiles, are young adults less than 24 years old.”

However, this latest study also noted that in countries that have strong regulations about who can go on the ice, when, and for what activity, such as Italy and Germany, they had lower incidences of winter drownings, than countries who didn’t have those rules in place.

“A lot of people assume that drowning is a summertime or swimming-related event, and it isn’t,” said Lifesaving Society CEO Kevin Tordiffe in an interview. “Drowning can occur at any time, in any place or any environment you can be in.”