Temperatures have reached well past the zero mark, with some places already as low as negative 17 degrees.
As people head outside, it could become dangerous if people aren't safe.
"About 750 people in the U.S. die each year from hypothermia about 20 right here in Maine," said Susan Faloon, with Maine Emergency Management Agency.
Not all of those are outside.
About 3 to 4 of those incidents happen inside the home.
"Most people in the home that have problems with the cold have what we call Urban Hypothermia and we see that more often in elderly patients or patients with chronic diseases where they're not. Their bodies aren't as good as sensing the cold environment and they aren't as good as responding to the cold," said Jonnathan Busko, Medical Director of the E.R. at St. Joseph's Hospital.
Hypothermia can occur in temperatures colder than 65 degrees.
One of the early signs is shivering and as it progresses, it could lead to death.
If you're become hypothermic you could become frost bitten.
"If it's very cold those blood vessels in the ears and the nose they constrict down so they turn white or pale and they start to lose sensation," said Busko.
As temperatures continue to dip, people turn to alternative sources of heat causing cases of carbon monoxide poisoning to rise.
"Carbon monoxide is odorless and colorless. You won't know you're being exposed to carbon monoxide until you start to develop those symptoms," said Busko.
The symptoms are subtle.
It causes confusion, a mild headache, and nausea.
"The most important thing to do if you start to show symptoms of carbon monoxide poisoning is to get out of that environment," said Busko