Many who know him said that Francis, driven by a sense of mission and a discipline born of his early training, essentially worked himself into the hospital.

The 88-year-old pontiff suffered a “prolonged asthmatic crisis” and low platelets, the Vatican said, but was alert and sitting in an armchair.

Pope Francis remains in critical condition and “is not out of danger,” the Holy See Press Office announced Saturday evening in Rome. The 88-year-old pontiff “experienced an asthma-like respiratory crisis of prolonged intensity” Saturday morning that required the administration of high-flow oxygen, according to the Vatican’s medical update.