The sisters, aged 58 and 68, from Ireland and New Zealand, respectively, got into the malfunctioning lift at a nun's residence on Rome's Via Aurelia on Friday and were finally rescued on Monday morning.
"In order not to lose consciousness, they drank their own urine," a paramedic was quoted in Tuesday's print edition of La Repubblica as saying.
The pair, who had only arrived at Casa Suore Mariste a few days earlier, became trapped after the lift got stuck while making its descent to the ground floor.
But their cries for help proved futile as the building was empty, and remained so until a cleaner arrived early on Monday morning. They were also without a mobile phone.
The cleaner raised the alarm after ringing the doorbell of the home and not receiving a reply.
Once on the scene, the police obtained a spare set of keys from a nearby religious institute and entered the building.
One police officer headed for the staircase. “Is anybody there?” he shouted, only to be greeted by the feeble reply of the two poor nuns: “Yes, we're here. In the lift."
The women were rescued by the fire brigade and taken to San Carlo di Nancy hospital, where they were treated for severe dehydration. Temperatures in the capital hit 34 degrees Celsius over the weekend.
"The sisters were almost completely dehydrated," the paramedic added. "It's a miracle they were still conscious when the emergency services arrived."
As they boarded the ambulance they told police they had “prayed a lot”, in the hope that their guardian angels would arrive.
Their prayers were finally answered, although they might not make a habit out of using lifts from now on.