Most people get very confused between temperature and heat. No they are not the same thing.
Try imagining this...
You have a component producing heat and in this you can actually see the heat in the form of balloons. Now, if you have no air flow, the balloons stay on the component, more and more heat builds up and you have this enormous pile of balloons... you need to remove the balloons as they are made. So you create an airflow, pushing the balloons out of the way so that as more are produced they are blown away.
You then need to make sure that the balloons are continuously carried away AND that they don't sit in a dead spot somewhere. In your computer case you want air coming in at one end (usually the front) which pushes the balloons out the back. To improve the removal of the balloons from the case, people will put another fan at the back pushing air away from the case.
It doesn't matter that components feels wam or hot as such, it matters that heat is not allowed to build up by trapping it within the case. Cooling is about the removal of heat, temperature reduction is a side effect.
