This one might a bit controversial but I've witnessed its efficacy!
This comes from an ex-brother-in-law. Whenever he began to come down with a cold, he'd swig a small shot of whiskey then bundle up really warm. Sweatsuit, socks, beanie and a heavy blanket. Then, he'd go to sleep.
He insisted that he'd "sweat" out the cold and wake up feeling much better. The cold, if not gone, would be lessen in severity instead of worsening.
I think the alcohol, which is not only antiseptic, raised his body temperature which naturally killed off invading bacteria in his body. I don't want to pass along any questionable or dangerous old wives' tales, but he proved his theory every time he had a cold.
If you look at the ingredients of Nyquil and such, it contains alcohol, too.
Alcohol should never be given to infants and children. And, those with liver and kidney problems shouldn't imbibe alcohol either. There are health and religious reasons to abstain as well.
I just wanted to throw this tidbit out here to see if anyone else can provide insight as to why it worked.