Why is it so cold in the Antarctic and Arctic?

Because the earth is tilted, the angle of sunlight entering the poles is very large, which makes the unit area get less sunlight, resulting in no heat, so it is cold.

Secondly, the problem of extreme night.

It is also the above reasons that lead to the extreme night phenomenon in the north and south poles, that is, the sun is not seen at all all all day. It's winter.

White glaciers are also one of the incentives.