Temperatures may reach the low 30's today, but the wind chill could make it feel even colder.
While some struggle even after just minutes of walking outdoors, for the Occupy D.C. movement, sleeping in tents can prove potentially dangerous.
Tuesday night will be the coldest night since the start of the Occupy D.C. movement.
Protester John Canzangis does his best to layer up his living quarters and himself because, after all, this is only the beginning of winter's cold wrath.
"I was in the Marines," he says. "Very similar weather we dealt with when I was stationed there."
Dozens of Occupy Wall Street protesters have been camped out in McPherson Square since September.
"The winter will be our Valley Forge," said protester Ricky Lehner. "If we survive the winter, it [will] show how determined we are."
Some have tried to build wooden structures to block the cold, but police have knocked them down.
Yet it could be worse. In Michigan and Ohio, cold temperatures have come with more than 10 inches of snow.