Brief Answer:
Dehydration and hypothermia, seek medical attention soon

Detailed Answer:
Hello dear, welcome to Ask a doctor service.
I read your query and here is my advice.

The feeling of cold in your brain and in ears too is a sign that you are dehydrated.
Alcohol is a diuretic and causes you to loose water fast. This also can be a sign of alcohol poisoning that is a very serious situation.
You can measure the body temperature and if it is below normal you should seek medical attention soon.
Alcohol also damage the blood vessels of the brain and of ears and this can cause the feeling of cold.

Hope I have answered the question.
Let me know if I can assist you further.

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