The ideal temperature of water to cool down the burned area is

Cool the burn wound. This provides analgesia and slows the delayed microvascular damage that can occur after a burn injury. Cooling should occur for a minimum of 10 minutes and is effective up to 1 hour after the burn injury. It is a paicularly impoant first aid step in paial-thickness burns, especially scalds. In temperate climates, cooling should be at about 15degC, and hypothermia must be avoided Ref bailey and love 27e p620