CALGARY, AB (WCMH) – How cold is it? Cold enough for zoos to move penguins inside.

As bitter cold grips most of North America, zookeepers at Calgary Zoo in Alberta, Canada had to move their King Penguins inside after temperatures dropped below -13 degrees for several days.

According to Canadian newspaper The Globe & Mail, the penguins usually stay outside during winter, but handlers decided to err on the side of caution this year because of still-maturing penguin chicks.

While King penguins can tolerate the cold, the species is used to milder climates compared to their Antarctic-dwelling cousins, the Emperor penguin.

The cold weather has also been blamed for a pair of recent shark deaths, after conservation officials said two thresher sharks that washed up on the Cape Cod shore likely died of cold shock.