Today they announced his high fever from a bladder infection. Bladder infections and other infections are not uncommon when older patients are hospitalized frequently as the Pope has been.
The doctor on MSNBC said the Pope may have had a catheter--that's why my very ill brother-in-law spent a week in the ICU. He has a catheter and got a bladder infection on top of pneumonia. He survived, but he may be stronger than the Pope, but only marginally.