what is the effects on a magnet if you use different temperatures?

Question

tell me about magnets and what they do

Answer 1

I think magnetic field strength is inversely related to the temperature.
Heating a magnet causes it to undergo hysteresis.With increasing heat, the magnet will gradually lose magnetization until a certain temperature (called the Curie temperature) where the magnetization goes away entirely.
In addition to this effect, the domains of the magnet will have a greater chance of changing orientation, further weakening the overall effect.

Answer 2

At a high enough temperature, magnetism goes away, but I have not heard of any ordinary effects of temperature changes lower than that.
Magnets work because they line up the magnetic poles in the material attracted. If the poles can not align, the material is not magnetic.