Final answer:
In surgeries where water is not exposed to the environment, the water used must be sterile distilled water or sterile water for irrigation to prevent infection and ensure safety.
Step-by-step explanation:
The type of water used during surgery where none is exposed should be sterile distilled water or sterile water for irrigation. This water has been purified and sterilized to ensure that it is free from any microbes or particles that could cause infection or complications during a surgical procedure. Using sterile water is crucial since it comes into contact with sterile surgical instruments and potentially open surgical sites. In operations where no water is expected to be exposed to the external environment, sterilization remains key to prevent infections.