I hate to say it but I don't think it's possible to acclimate to the cold. It's not like we're going to grow fur or anything! A scientific argument would be that of homeostasis. Metabolism in the body is conducted at a very consistent 98.6 degrees. Turn the heat up or down, you're still going to be 98.6 degrees (unless you're fighting an infection). The body doesn't want to be anything else. That's why we shiver when we're cold and sweat when we're hot. The body puts up a good fight to resist change. That said, my cousin comes up from Florida and can't cry enough about how cold it is here. He also rants about how his blood got thin living in Florida and how all the hundred year olds Willard Scott says happy birthday to on tv are from up North here where the cold makes us more hardy people. I think it's BS.
I'm not sure I totally agree with you here about acclimating to the cold. Perhaps the term "acclimation" is not entirely precise, but I'm pretty sure the basic concept is sound.
As you, yourself mentioned, people from warm climates tend to complain bitterly about even slightly cool temperatures, not to mention what they do when they get a chance to experience real cold. Such people also seem to be more prone to hypothermia than those who spend a lot of time in the cold. I routinely go outside and recreate in temperatures that would literally paralyze my younger brother (who lives in sunny southern Kalifornia).
People who live at higher altitudes (which are usually colder) generally have more red blood cells than do people living at lower altitudes. This is because the air there is thinner and so; more red blood cells are needed to get enough O2 to the body. Many endurance athletes purposely live and train at higher altitudes so that when they go down to lower altitudes to compete, their blood is thicker and can carry more O2, which in turn allows them to perform better. It's essentially a "legal" way to "blood-dope." Perhaps this higher quantity of red blood cells and subsequent higher levels of O2 also helps explain this idea of "acclimation to cold."
