Under a Code Blue, outreach teams head out overnight to check on anyone sleeping outside or in the subway system. If you see someone who might need help, officials say you can call 311 to get them connected to shelter.

For those staying indoors, city officials are reminding residents that heat season rules are in full effect. If the temperature outside dips below 55 degrees, your landlord must keep your apartment at least 68 degrees during the day. Overnight from 10 p.m. to 6 a.m. the temperature inside must stay at least 62 degrees, no matter how cold it gets outside.

You should also always have hot water, even in the middle of winter. If that’s not the case, the city says to reach out to your building’s super first — and if it’s not fixed quickly, file a complaint by calling 311.

City officials are also urging New Yorkers to check on neighbors, especially older adults or anyone who might have trouble getting around or turning on their heat.