Umm Sulaim, what is this? She said: It is your sweat, which I put in my perfume. Allah's Apostle (ﷺ) sweated in cold weather when revelation descended upon him.
Sahih Muslim Book 43, Hadith 115
← Previous Hadith It is Allah's Apostle (ﷺ) who is having siesta in your house, lying in your bed. She came and found him sweating and his sweat falling on the leather cloth spread on her bed. She opened her scent-bag and began to fill the bottles with it. Allah's Apostle (ﷺ) was startled and woke up and said: Umm Sulaim, what are you doing? She said: Allah's Messenger, we seek blessings for our children through it. Thereupon he said: You have done something right.

Sahih Muslim Book 43, Hadith 114 Next Hadith → When revelation descended upon Allah's Messenger (ﷺ) even during the cold days, his forehead perspired.

Sahih Muslim Book 43, Hadith 116