Hot vs. Cold Stretching Shoes test (Video)

Since I had purchased two new pair of shoes that both needed stretching, I decided to test two methods, one hot and one cold.

I could not get the .mov iphone videos to convert so that I could put them together in one video, so here are two videos, the introduction first:

Which is better? Here is the result video:

Yes, the hot method works better!

Now, who are the scientist readers here who can tell me why the hot method of expanding works better than the cold method of expanding and why does both hot and cold expand?