Umm Sa'ib or Umm Musayyib. why is it that you are shivering? She said:" It is fever and may it not be blessed by Allah, whereupon he (the Holy Prophet) said: Don't curse fever for it expiates the sin of the children of Adam just as furnace removes the alloy of iron.  

أَنَّ رَسُولَ اللَّهِ ﷺ دَخَلَ عَلَى أُمِّ السَّائِبِ أَوْ أُمِّ الْمُسَيَّبِ فَقَالَ مَا لَكِ يَا أُمَّ السَّائِبِ أَوْ يَا أُمَّ الْمُسَيَّبِ تُزَفْزِفِينَ قَالَتِ الْحُمَّى لاَ بَارَكَ اللَّهُ فِيهَا فَقَالَ لاَ تَسُبِّي الْحُمَّى فَإِنَّهَا تُذْهِبُ خَطَايَا بَنِي آدَمَ كَمَا يُذْهِبُ الْكِيرُ خَبَثَ الْحَدِيدِ