Air conditioning at a five-story affordable, low-income housing building in Old Town malfunctioned Saturday, leading officials to offer to relocate residents.

About 7:35 a.m., firefighters responding to an unrelated call discovered that the air conditioning at Mercy Housing, 1244 N. Clybourn Ave., wasn’t working, as temperatures rose into the 90s, Chicago police and fire officials said.

Building management informed Chicago firefighters that the air conditioning unit in the building would need repairs and was expected to be out for at least two more days, fire officials said.

CTA cooling buses were ordered for the residents and firefighters went to each unit offering to relocated them to a different location provided by the management, police said.

One person out of of the 96 total residents decided to relocate, fire officials said. Another person was taken to Northwestern Memorial Hospital for treatment of a condition that wasn’t heat related.