Johnny Pickrell, 4, sticks out his tongue to catch snowflakes as he leaves Costco in Summerlin with his mother, Courtney, on Friday. After a cold front moved into Southern Nevada on Friday, snow flurries were seen in parts of Summerlin, Henderson and Red Rock Canyon, but none of the flakes stuck. Photo by Jane Kalinowsky. Denise Waller, 37, tries to stay warm Friday in the courtyard of the Salvation Army on Owens Avenue near Main Street. Waller, who is homeless, said she would sleep on the sidewalk outside the facility on Friday night despite the freezing temperatures. Photo by K.M. Cannon.

Angie White came to Las Vegas to warm up.

A resident of Pueblo, Colo., White escaped snow and temperatures near zero in her hometown this week, expecting to exchange her heavy winter coat for a breezy summer dress.

But the 43-year-old was bundled in a thick snow-white jacket on the Strip on Friday afternoon as Las Vegas was hit with a chilly cold front and freezing temperatures.

"This is terrible because I expected it to be warm," she said.

An arctic air mass from Alaska arrived on Friday morning, bringing bitter cold and light snow flurries in some parts of the valley, said Barry Pierce, a meteorologist with the National Weather Service in Las Vegas.

The high temperature on Friday afternoon was 45 degrees, but it was expected to plummet to as low as 18 degrees in some parts of the valley overnight, he said.

Today is expected to be sunny and cold, with a high of 40 and overnight lows in the 20s.

It's the coldest weather in Southern Nevada for this time of year in four years.

The weather isn't record-breaking, however. The record for Jan. 13 was set in 1963, when the temperature dropped to 8 degrees.

"Thank goodness we're not flirting with that," Pierce said. "We could have some serious pipe issues with temperatures that low."

Although light snow was seen around parts of Summerlin, Red Rock Canyon and Henderson, none stuck.

Snow did have a chance to accumulate on Mount Charleston. The weather service said the mountain received about 2 inches by 5 p.m. Friday. The weather service didn't expect any more snow to fall on Mount Charleston on Friday night or today.

Homeless advocates were mobilizing to protect people from the bone-chilling cold. Shelters were handing out blankets, coffee and hot soup to help people deal with the cold.

Shelters have been filling to capacity at night, and authorities were discussing whether to open Hollywood Recreation Center, at Sahara Avenue and Hollywood Boulevard, as a makeshift shelter to handle the overflow this weekend.

Service providers were to decide late Friday whether the extra shelter was needed.

Catholic Charities of Southern Nevada has 200 winter shelter beds but has been housing up to 380 people a night. Agency officials were trying to make space for up to 600 people this weekend. Many people have been sleeping on the agency's dining room floor. Catholic Charities opens its shelter around 5 p.m. each day.

The Salvation Army, which has about 300 emergency shelter beds, begins admitting people at 8 p.m.

The Las Vegas Rescue Mission has 48 beds, and an additional 40 or so would be housed in the chapel this weekend. People can go to the shelter beginning at 5 p.m.

But many homeless people had no plans to enter a shelter, even with freezing night-time temperatures.

"The (shelter) living conditions are outrageous," said Denise Waller, a 37-year-old homeless woman. "Last time I went in, I was sick the whole time."

Waller, who was hanging out with other people along the "homeless corridor" at Main Street and Owens Avenue on Friday, was huddled in a dirty down jacket over six layers of clothing. She planned later to retrieve her sleeping bag and "six or seven blankets" from a nearby field where she had stashed them. She was going to bed down on the sidewalk.

"I'm probably going to need all of them (blankets) tonight," she said. "Everybody's talking about the cold."

People weren't the only ones bundling up against the cold. The Southern Nevada Zoological and Botanical Park, on Rancho Drive near Lake Mead Boulevard, recently started heating Terry the chimpanzee's 200-square-foot den because of the cold, said Pat Dingle, director of the zoo.

The other animals, including tropical birds, apes, lizards and big cats, aren't affected by the cold or are housed indoors, he said.

That left Terry -- who also was given wool blankets that he makes into a nest in his den.

"He looks like a big bundle of laundry" under the blankets, Dingle said. "He's about 5 foot 6 inches and weighs 200 pounds. That's a big bundle of laundry."