Cold weather tricks

The drop in temperature provided many with the opportunity to conduct some unusual experiments.

Several readers sent in submissions to CNN's iReport where they demonstrated the effects of the weather by tossing boiling water into the air and watching as the mist particles froze in midair.

A reporter with CNN affiliate KVLY in Fargo-Grand Forks, North Dakota, used a frozen banana to hammer a nail. It worked.

Others took soaking wet T-shirts, draped them on hangers and watched as the cold air quickly froze them stiff.

Chicago firefighters hosing down a burning warehouse blaze ended up encasing the building in inches of ice.

The cold weather was good news for those who sell hot coffee for a living.

"On days like this, coffee sells. Bagels don't," said Sami Akramia, a 41-year-old food cart worker bundled up in Midtown Manhattan as the temperature dropped to 4 degrees Wednesday.

Deadly consequences

National Weather Service forecasters say they expect the cold weather to last throughout the week and urged caution. The frigid weather can have deadly consequences.

Authorities say exposure to subfreezing temperatures left at least three people dead in Wisconsin, Minnesota and Illinois.

"Those people who work outside have to be careful," said CNN meteorologist Chad Myers. "We feel the wind chill, and so do pets. You need to find some place indoors and out of the wind for them."

In New York and New Jersey, homes destroyed by Superstorm Sandy in places such as New Dorp, Staten Island, and Far Rockaway, Queens, lacked basic utilities needed to restore heat.

In the northern Maine town of Presque Isle, temperatures hung around 24 below Fahrenheit. And in Grand Forks, North Dakota, residents bundled up to stave off a potentially deadly wind chill that hovered even lower, around 33 below.

"The biggest thing is staying out of the wind. That's what kills you," said Michael Lannen, who works at a Menards hardware store in Grand Forks.

"It seems we get one of these kinds of weeks every year, so everyone is just trying to bundle up and stay indoors."