After cooking using a pressure cooker, it usually takes a while for the pressure to be released and for the cooker to be opened. However when I think the food may have been slightly overcooked, I take the pressure cooker from the stove and put it under running cold water from a tap. Within a few seconds, I am able to easily remove the lid off the cooker.
Why does reducing the temperature on the surface of cooker help me accelerate the reduction of pressure inside the cooker? Is this method safe?