Are people from extremely cold countries generally tougher than people from warmer countries?

Their toughness wears down if you change their places.

Define tough.

People are essentially the same, but they are affected by their environment in different ways.

Only in stupid Hollywood movies about "vikings."

Oh absolutely, i met an antarctican once and that penguin kicked the **** out of my uncle bob

On the contrary, people from the cold countries suffer more from mental issues having to putting up with severe cold winters and not seeing the sun on rainy days.

We'll see how tough they are when they come to desert where I live. They won't make it for 10-minutes outside during July and August.

There is no sign of this whatsoever.

I suggest that someone is just feeding themselves a line of horsecrap.