I'm trying to change the engine oil but running into difficulties removing the oil drain plug. One of the instructions I followed to change the engine oil was to give the car a short drive prior to the oil change; this would heat up the oil so that it would flow more readily into an oil drain pan.

Since I am having difficulties removing the plug, I was wondering if the heat has caused the oil drain plug to expand and tighten itself to its surrounding? Is it better to attempt to remove the oil drain plug when it is in a cooled down state?