Yahya related to me from Malik from Hisham ibn Urwa from Fatima bint al-Mundhir that whenever a woman who had a fever, was brought to Asma bint Abi Bakr, she made dua for her and took water and poured it inside her collar. She said, "The Messenger of Allah ﷺ ordered us to cool it with water."
أَنَّ أَسْمَاءَ بِنْتَ أَبِي بَكْرٍ كَانَتْ إِذَا أُتِيَتْ بِالْمَرْأَةِ وَقَدْ حُمَّتْ تَدْعُو لَهَا أَخَذَتِ الْمَاءَ فَصَبَّتْهُ بَيْنَهَا وَبَيْنَ جَيْبِهَا وَقَالَتْ إِنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَأْمُرُنَا أَنْ نُبْرِدَهَا بِالْمَاءِ