-25 degrees celsius

How does one prepare ones self for sub-freezing temperatures after years of living in the tropics? I thought I had been in cold weather before but that was until I went to Mongolia in the middle of winter. I'll never forget getting off the train in Mongolia and asking to myself, WTF am I doing here? It was like hitting a brick wall.  I soon found out that there are different levels of cold. There's the cold that makes you feel alive, there's that taste of a cold beer running down the back of your throat on a hot summers day, there's cold days meant for brisk walks, then there's Mongolian cold: so cold that it hurts to breathe, instant brain freeze.