What action helps to cool a hot door before opening?

Pouring cold water on a hot door is an effective method for cooling it before opening. This action introduces a significant temperature difference, which helps to reduce the heat of the door's surface. The cooling effect of the water can potentially prevent sudden flare-ups or backdrafts that may occur if the door is opened without this precaution. This technique is particularly important because it stabilizes the situation, allowing for a safer environment when proceeding further into an area that may contain fire.

Other methods, such as covering the door with a wet cloth or using a fan, may provide some cooling, but they are not as direct or effective as pouring water. For instance, a wet cloth might not sufficiently absorb enough heat to lower the temperature safely, and while a fan could help circulate air or dissipate some heat, it would not provide the immediate cooling effects that cold water does. Using an extinguisher on the door can be inappropriate in this context since extinguishers are designed for putting out fires, not cooling hot surfaces.