What is the ruling on having a sauna (steam bath) during fasting?
All perfect praise be to Allah, The Lord of the Worlds. I testify that none is worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
The Maliki scholars stated that a fasting person is not allowed to inhale the steam that comes out of a heated pot. They also stated that in case he does and the steam reaches his throat, he is required to make up for that day. They argued that the steam is a substance that gives strength and feeds the brain in the same way as food does. According to Ad-Dusooqi when one deliberately allows steam to reach the throat, fasting is invalidated. [Haashiyat Ad-Dusooqi]
Based on this argument, inhalation of steam in the sauna invalidates fasting; as it is a kind of water that reaches the throat through the mouth and nose.
Accordingly, we are of the opinion that it is more prudent to delay having a sauna to the nighttime, if one needs it.
Allah Knows best.
You can search for fatwa through many choices