Liz Hersh with the City of Philadelphia says the initiative takes extra steps to keep homeless people safe.
"People don't have to leave shelters during the day. There's extra outreach available, so the whole idea is about keeping people warm and safe when the weather is really dangerously cold," Hersh said.
Homeless people are also allowed to stay inside emergency housing throughout the day.
If you see a person who appears to be homeless during a Code Blue, call the outreach hotline at 215-232-1984.
"Tell the location where the person is and we will get a team out there as soon as possible to try and get them," Hersh added.