If this weather extreme were in the opposite direction, someone would probably be talking about frying an egg on the sidewalk.

So National Weather Service meteorologist Aaron Tyburski, after speaking with a York County reporter who posed the challenge Monday morning, decided to see how long it would take to freeze an egg in Monday night's subzero temperatures.

He placed it outside his State College house, where temperatures were equally as frigid as in York, on a sheet of foil because he didn't want to have to clean it up when the weather warms.

"The egg project worked well," he reported Tuesday morning. "The egg whites froze within seconds and the yolk took about an hour or so. ... In the morning it was like a hockey puck."

That scientific endeavor aside, Tyburski said it's probably not very wise for anyone to be outside for very long.

The dangerous cold brought by an Arctic air mass has broken records and poses a serious danger of frostbite and hypothermia to anyone exposed without proper gear.

Monday night's minus 3 low broke the record logged for the York area on the same date 72 years ago (1942), when it was 2 degrees, Tyburski said.

Wind chills in York were minus 20-25 degrees, and the high Tuesday wasn't expected to break 6 degrees, he said.

But in a keeping with the seven days of extremes that has represented the first week of 2014, the cold was expected to give way to 50-degree temperatures by Saturday, he said.

The overnight low into Wednesday was expected to remain about 6 degrees, with Wednesday hitting the 20s, Thursday hitting the 30s, Friday hitting the 40s, and Saturday and Sunday possibly hitting the 50s, Tyburski said.

Staying warm: York Rescue Mission at 367 W. Market St. has seen an increase in the number of transients staying at its shelter since the cold weather moved into the area, said executive director the Rev. Paul Gorog.

He said about 18 or 20 people typically spend the night, but there were 27 on Monday night.

That's up from 23 Sunday night and 20 Saturday night, he said.

The shelter had some extra room, he said, so he assumes everyone who needed a warm place to sleep had gone to the shelter.

Those who came in from the cold described it as "Cold, cold, cold, double-cold, brrrr," he said.

Spokesmen at both Memorial Hospital and York Hospital said they weren't treating anyone for weather-related ailments such as frostbite or hypothermia.

"Typically people do pay attention, and there's a lot of information out there about what to do in this extreme cold weather," said Barry Sparks, York Hospital spokesman.