1) Water in a Mikveh (Ritual Purification Pool) or spring, is not rendered unfit for use if used for a different purpose, and one may immerse one’s hands therein, or even remove water and use it for washing one’s hands. (Shulchan Aruch and Mishne Berura 160)
2) One may wash one’s hands with water that has been heated in a fire. If the water has reached the temperature called Yad Soledes Bo, some say that it may not be used and others permit it. If one has no other water, one should not be stringent. (Mishne Berura ibid)
