Khalid bin al-Rabi, reported that when the illness of Huzayfah became serious his group and the Ansar heard of it. They visited him at night or in the (early) morning. Sayyidina Huzayfah asked, "What time is it?" They said, "It is midnight or nearing morning." He said, "I seek refuge in Allah from the morning which heralds admittance to Hell." He then asked, "Have you brought the cloth? Do no shroud me in costly (cloth), for if there is good for me with Allah then I will be given a better replacement but if it is the other way then even this will be taken away quickly".
It is narrated by Ayeshah (ra) that the Prophet (ﷺ) said, "when a Muslim is afflicted by an anxiety, pain or sickness then, because of
that, his sins are atoned. So much, so that if a thorn pricks him or he suffers a simple, minor injury (His sins are forgiven)”.
Abu Hurayra said, "A bedouin came and the Prophet, may Allah bless
him and grant him peace, asked, 'Has Umm Mildam (fever) got hold of you?'
'What is Umm Mildam?' he asked. He said, 'The heat between the skin and
the flesh.' The bedouin said, 'No.' He asked, 'Have you got a headache?'
'What is headache?' the man asked. He replied, 'A wind which appears in
the head and beats the veins.' 'No,' he said, When he stood up, he said,
'Whoever wants to look at a man who is one of the people of the Fire,'
i.e. 'let them look at that man.'"