From the first moment the doctors of the bedchamber Vega and Olivares treated him, and also the Licentiate Deza Chacón, surgeon to the King; and, as the Prince complained very much when he was being bandaged, the surgeon rather stayed his hand. Quijada, who always thought badly of the wound, said, "Tighter, tighter, Licentiate Deza. Do not treat him as a prince, but as a peasant."
D. García de Toledo at once sent off one of the Prince's gentlemen of the bedchamber, D. Diego de Acuña, to tell the King what had happened, and by daybreak the next day, Monday, the 20th, he had already returned with Dr. Gutiérrez, first physician to the King, and the doctors Portugues and Pedro de Torres, his surgeons.
A few hours afterwards the King arrived in person, and in his presence all the doctors examined the wound; they unanimously declared that it was not dangerous; and, reassured by this, D. Philip went back to Madrid that same night.
But at daybreak on the 30th, the eleventh day, a high fever seized the Prince, with severe pains in the wound, neck, and right leg, which otherwise seemed dead.
The doctors were frightened, and then declared that the symptoms revealed a lesion in the skull, if not in the brain.
Hastily the King was informed of this, and the same night, the 30th, he arrived at Alcalá with the Duque de Alba, the Prince de Évoli, and Charles V's former doctor, Vesale. A few hours later came the rest of the Council and the Grandees who held offices at Court.
The Prince was so ill on the 2nd of May that the King ordered the sacraments to be administered to him; his face was inflamed, swollen eyelids made him blind, and his right leg was completely paralysed.
D. Carlos received the Viaticum with great devotion, and, clearing the room, made signs to D. John of Austria to come near him.
Taking his hands affectionately the Prince whispered to him that he had offered to Our Lady of Montserrat his own weight in gold and three times his weight in silver if he got well; and that he had also made the same offerings at the sanctuary of Our Lady of Guadeloupe and to the Christ of St. Augustine in Burgos; but that there was there in Alcalá, in the convent of the Franciscans of Jesus and Mary, the body of a great saint, who was called Brother Diego, to whom he wished to make the same offering, and he begged D. John, as he loved him, to go himself and make this offering at the saint's sepulchre in D. Carlos's name. Much touched, D. John promised, and from that day he went morning and evening to beg for the Prince's recovery before the sepulchre of Fr. Diego. The illness had changed the miserable D. Carlos; he became docile and gentle, obeyed everyone, and asked pardon, especially of his father and Honorato Juan, the only person, perhaps, that he really loved.
He liked D. John of Austria and the Prince of Parma to be always at his side, and when, from exhaustion, he could not talk to them, he took their hands and fondled them.