Purity: Wudu with Minimum Water to Avoid Harm
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 288:
If a person would not be harmed by washing his face and arms with the minimum amount of water with which performing wuḍūʾ is valid but he would be harmed by using an amount more than that, he must perform wuḍūʾ with the minimum amount.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)