Whenever Messenger of Allah ﷺ became sick, he would recite Mu'awwidhat (Surat Al-Falaq and Surat An- Nas) and then blow his breath over his body. When he became seriously ill, I used to recite (these two Suras) and rub his hands over his body hoping for its blessings.  

أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ إِذَا اشْتَكَى يَقْرَأُ عَلَى نَفْسِهِ بِالْمُعَوِّذَاتِ وَيَنْفُثُ فَلَمَّا اشْتَدَّ وَجَعُهُ كُنْتُ أَقْرَأُ عَلَيْهِ وَأَمْسَحُ بِيَدِهِ رَجَاءَ بَرَكَتِهَا  

Whenever the Prophet ﷺ went to bed every night, he used to cup his hands together and blow over it after reciting Surat Al-Ikhlas, Surat Al-Falaq and Surat An-Nas, and then rub his hands over whatever parts of his body he was able to rub, starting with his head, face and front of his body. He used to do that three times.  

أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا أَوَى إِلَى فِرَاشِهِ كُلَّ لَيْلَةٍ جَمَعَ كَفَّيْهِ ثُمَّ نَفَثَ فِيهِمَا فَقَرَأَ فِيهِمَا {قُلْ هُوَ اللَّهُ أَحَدٌ} وَ{قُلْ أَعُوذُ بِرَبِّ الْفَلَقِ} وَ{قُلْ أَعُوذُ بِرَبِّ النَّاسِ} ثُمَّ يَمْسَحُ بِهِمَا مَا اسْتَطَاعَ مِنْ جَسَدِهِ يَبْدَأُ بِهِمَا عَلَى رَأْسِهِ وَوَجْهِهِ وَمَا أَقْبَلَ مِنْ جَسَدِهِ يَفْعَلُ ذَلِكَ ثَلاَثَ مَرَّاتٍ