The paternal aunt of Abu Ubaydah bin Hudhayfah (may Allah be pleased with her) said: I went in to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) had a fever. He (peace and blessings be upon him) ordered a water-skin to be brought, which was hung on a tree; then he (peace and blessings be upon him) lay down beneath it, and the water began dripping onto his (peace and blessings be upon him) heart. I said: O Messenger of Allah, if only you would supplicate to Allah to remove this from you. He (peace and blessings be upon him) said: "Among the people most severely tested are the prophets, then those who come after them, then those who come after them."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21000