Abu Hurayrah said that he did not like any illness more than fever because it went into each of his limbs. And, Allah grants each limb its share of reward.

وَعَنْ عَطَاءٍ، عَنْ أَبِي هُرَيْرَةَ قَالَ‏:‏ مَا مِنْ مَرَضٍ يُصِيبُنِي أَحَبَّ إِلَيَّ مِنَ الْحُمَّى، لأَنَّهَا تَدْخُلُ فِي كُلِّ عُضْوٍ مِنِّي، وَإِنَّ اللَّهَ عَزَّ وَجَلَّ يُعْطِي كُلَّ عُضْوٍ قِسْطَهُ مِنَ الأَجْرِ‏.‏