I saw an article a while ago now on the net that was headed "Can drinking ice water help boost metabolism?".
It ended up being a video and she was introducing herself, I'm thinking, great, she is going to go against what everyone thinks and say 'NO', however, she ranted on for over 3 minutes about how you will lose weight and look and be amazing!!
Let's look at this from another point of view. The view of 'No!!!".
Okay, sure, cold water will make your metabolism increase initially and you may lose weight. BUT…. our stomach needs to be kept warm in order to function. This is well known amongst anyone who has studied even a small amount of Traditional Chinese Medicine (TCM). You would be far better off to have a small amount of warm tea or even better, miso soup before meals which will prepare the stomach for the food you are about to eat and to better help you absorb nutrients from that food.
Cold water, whether before meals (which would be the worst time to have it) or at all during the day, destroys your stomach energy making you unable to absorb food properly and will eventually destroy your metabolism. I am aware of 'research' that shows you lose weight and you will definitely find people that swear by drinking ice cold water to lose weight. This is not for long-term results and people who do this will find they have other digestive issues start to creep up. Issues might include stomach ulcers, slow digestive, constipation, irritable bowel syndrome, kidney stones -- just to name a few… I wish 'research' were extended to look at these things.
If we make our stomach energy cold, you are also negatively affecting your spleen energy (the partner to the stomach in TCM). The spleen/pancreas energy basically controls your digestion, decides if it will turn the food into fat or muscle and it has a LOT to do with the menstrual cycle. Drinking cold water can chill the pelvis and also contribute to period pain, endometriosis, infertility and other women's health issues.
Warm water is also the best way to rehydrate as it goes to the skin and the capillaries.
As with all advice, it is best for you to try it yourself and see if it works. We have to stop listening to everything we hear or read and believing it as truth. 'Non-credo' - basically translates as don't believe everything at face value. Try it out as you should be your only judge...