Why does temperature effect the strength of a magnet?

Question

I know that magnets are stronger when they are colder and become weaker as they increase in temperature. Can anyone explain to me why this happens? THX!

Answer 1

The permiability of a metal has a curie point.
At that temperature, and abrupt change occurs where the permiabilty drops basically to 1.

http://en.wikipedia.org/wiki/Curie_temperature

Answer 2

The high temperature means high KE (kinetic energy) the movement of the particles moves the magnetic alignment of the "domains" of the substance, iron or whatever, and thus the magnet losses its strength. That's why superconductors need to be below zero in temperature to work properly.