Why do people say blue is cold and red is hot

Well I wanted to know why people say blue is cold and red is hot.

I think why people say that because  lets say you in the North and South Pole it's cold and the white snow has a little bit of blue that is why people say blue is cold that is my opinion.

But red hot I think people say that because you know the sun and fire and lava is red and there hot.

 Well that is why people say red is hot. But people say warm is yellow because in warm places they have more yellow stuff then green,blue and red stuff.

And people say cool is green because in cool places there is more green then blue,yellow and red. We all know that the equator is hot because of where the sun hits it.

South and North Pole move father away from the sunlight. Well I heard the North pole is warmer
then the South Pole because it's closer to the sun.

The South pole has more Penguins because I heard most Penguins live in South Africa because it's warm and South Africa is close to the south pole. Water freezes at 32 degrees.

Or maybe there was this kind of bird and then they change into a penguin bears are a lot in the North and that is why there in the North Pole. Poles bears live in the north because they have thick fur.

Well Polar Bears live more in the North Pole Probably because More bears live closer to north then birds.

I heard if it's really cold and freezing people skin gets blue and if it's really hot your skin will get red by being in the sun to long.