Cold vodka - I have got some scientific theory to prove it. The science behind it is that in order to cool down to normal body temp it is best to drink water which will bring your temperature as close to 98.6 degrees F as possible without dropping it down more than that....the reason being is that drinking water which will cool your body to optimum regular temperature exerts no energy on the body. on the other hand drinking ice cold water drops the inside of your body's temp below 98.6 degrees and your body has to exert energy in order to warm the liquid in your body back up to regular body temp. as far as water is concerned on the molecular level, the H2O molecules move faster in warm water than in cold water...meaning they will be absorbed into your body faster with warm water, than cold water, because the the atoms of the molecules are moving faster. However....it depends on what you're drinking the water for... simply drinking cold water alone can help you loose weight because your body has to exert stored energy to warm it like i mentioned before.....if you were to drink about 40 glasses of ice warer a day...every day for a year....with no exercise, the energy your body would have to use to heat the water up to your normal body temperature would cause a weight loss of about 3 pounds.