Q: Why does alcohol make me warm when I drink it?—Blake N., Stockton, Calif.
A: There are several causes for that warm, cozy feeling you get when you have a glass of wine, but the primary reason is that alcohol is a vasodilator, which means that it increases blood flow, especially in the blood vessels near the skin. The effects of that increased flow of blood can range from a mild sense of warmth to sweating to flushed skin. That's theorized to be one of the reasons that higher levels of alcohol consumption have been linked to colder climates.
However, that feeling of warmth radiating from your skin is a signal that blood is being diverted from your core, and an indication that your body temperature may actually be lowering.
It's also important to note that warmth is generated by activity in the core organs as well as in the heart, brain and liver, and internal body actions like digestion have temperature-altering properties. When the digestive process reaches the liver, blood flow to the organ is increased to aid the metabolic process. When alcohol is added to the mix, the liver's workload increases, demanding even more circulatory assistance and causing an overall drop in body temperature.
Lastly, alcohol is a depressant, and can hinder the part of the brain that senses and controls body temperature, which can fool you into feeling warmer than you actually are.
For these reasons, drink with caution in extreme temperatures: That comforting feeling can be misleading.