If you are asking about "finished iced coffee", it is ok to brew it with mineral water at room temperature, but the taste will fade and it will not taste good.

If you ask about the technology of "cold extraction" and "ice drops" to make "iced coffee", normal temperature mineral water can't be made.

"Ice drops" need to be slowly dripped by ice water close to 0 degrees for extraction. "Cold extraction" requires mixing coffee powder with mineral water, then putting it in the freezer, refrigerating it for more than 24 hours, and slowly extracting it. If extracted at room temperature, it is a cup of bitter water without fragrance.