Hypothermia occurs when your internal temperature falls below 95 degrees, to a point where your heart, nervous system, and other vital organs can’t function normally — if untreated, it can lead to heart or respiratory failure. Other cold-related injuries include frostnip, frostbite, nerve damage, and loss of appendages, Raslau says (and here's one example). It can happen at as high as 50 degrees fahrenheit, but it's much more common in lower temperatures below freezing or 32 degrees fahrenheit.
Obviously, this all depends on how much alcohol you drank, how cold it is outside, and how long you're exposed to the cold, Warren says. We're not trying to be paranoid here or insinuate that you'll get hypothermia every time you step outside with no jacket. But if you're going to be out in the cold for more than five minutes, or you plan to walk to and from places while drunk, bundle up appropriately.
Alcohol-related hypothermia is more common than you think, the experts say, especially at colleges. “People have died from hypothermia after drinking because they don't know their core temperature is dangerously low, then they pass out or fall asleep drunk outside,” Warren says. So your risk is higher if you're alone, since this could happen with no one noticing.