Hot water

Literally if you mix cold and hot water, the water will be lukewarm and it is not bad to your health. If you are saying that if you drink cold water then you will also drink hot water next for me it is not good. Mixing drinking of cold and hot is not good for your teeth, that is only my opinion If you drink hot, just don't drink cold after it.

if u can be accustomed to it,well i think it will be alwright.

Just think it like this way how would you feel when you drink cold water first and then hot water.just think about your stomach will feel.The same way will happen with your head

I think using of hot water whether its good or harm for our body is depend on our condition. If we're fit, then nothing to worry. But if we got flu or fever during the winter season, then it's better don't use it directly to our head. Just use it to washing our face. Also, for high blood pressure sufferer should more carefully. Better having bath in fit condition. Warm water is good but usually after we finish the bath, everything will be back to normal, which is cold on winter season. Have a nice day and happy mylotting.