Shelters in Denver served more than 1,446 people Thursday night, according to the Denver's Road Home.
Spokeswoman Julie Smith said shelters served around 1,400 on Wednesday night as well.
The city has seen record cold this week, with Thursday morning temperatures dropping well below zero.
Andrew Spinks, development director of the St. Francis Center, said Thursday that this year's cold snap seemed to catch people by surprise on Monday.
When extreme cold weather hits, Spinks said that many people who normally will not come in "at all," seek shelter. Others are "very prepared all the time and understand that Colorado has this pretty severe changes or shifts in temperature," Spinks says.
"We're running behind in coats and gloves [more] than we ever have at this time of year because of this weather," Spinks says.
Denver Rescue Mission reported serving record numbers of people at the Lawrence Street Shelter this week, including 1,168 people on Wednesday night.
But for people who are concerned about someone who is still out in the cold, Spinks recommended calling police.
Denver Police Spokesperson Christine Downs explained that when extremely cold weather hits, homeless outreach officers work with resource officers to get homeless people to shelter in the day or night.
"If anyone has some if they would like us to check on, they can call and give us the location and a description -- if that person appears responsive or if they need medical attention rather than just health -- they can just call," Downs says.