Last night I went out for a meal in a nice restaurant with my boyfriend. After a three course meal with two units of alcohol we drove home. We both felt very cold, despite being well wrapped up in a relatively warm car. On closer introspection, I realised that all my muscles were extremely tense, and I wasn't actually all that cold. I was completely unable to relax physically, even though I was totally at ease emotionally. My boyfriend reported the same sensation. I recall feeling the same way on many occasions after leaving restaurants.

Can anybody offer an explanation or indeed a remedy?