Sagot :

The reason why the coldest places on earth are found on poles is because they are too far away from the equator. Places near the equator, will receive more direct sunlight than the far ones from the equator.

Hope this helps =)
Because Poles are mostly found at the northern and southern hemisphere of the earth where there is a little amount supply of light (aurora) and heat that is coming from the sun. Also, the enough supply of heat and light that's coming from the sun can be felt to the countries near the imaginary line called equator.