According to this article, it was mentioned:
there may be advantages in drinking cold water for weight loss
So, does drinking cold water really help to reduce weight? and does drinking warm water really help to increase weight?
TL;DR: No, not to any large extent - the effects are swamped by other, much larger factors.
In this study, the energy expenditure of some young subjects were measured before and after drinking 500mL of distilled water, saline, sucrose and cold (3°C) water.
Warning: The abstract does not detail the size of the sample, except noting it was a subgroup of the main experiment.
But, we are talking about the human body, so it is more complicated than that. If you want to lose weight by increasing your energy expenditure, exercise is a major factor. If you want to exercise for long periods, ensuring you aren't dehydrated is a major factor. Which brings us to another effect of water temperature.
Fourteen men were offered 15°C water, 40°C water, 15°C flavored water, and 40°C flavored water while doing six hours (on-and-off) of treadmill exercise. The men were divided into two based on whether they tended to replenish the weight lost through sweat ("Drinkers" or D) or not ("Reluctant Drinkers" or RD). Both groups drank significantly more water when it was cold.
Note: The short-term body-weight loss here is presumably mainly water-loss not fat-loss.
The definition of cold varies between the two studies cited. Which brings us to another interesting study.
They offered water at a range of temperatures to some people dehydrated through sweating or mountain climbing, measured how much they drank, and asked what they preferred.
The subjects rated the coldest water as more pleasurable, but drank more when they drank it at 15°C. If given the opportunity to mix the water to a drinkable temperature, they also chose 14.9°C. This contradiction between drinking the most at 15°C but rating 0°C as more pleasurable was attributed to the volunteers being too hot as well as dehydrated:
Yes, drinking cold-water may help with weight loss, however this will probably be less effective than you'd like, and almost ineffective if used in isolation of greater diet reform and exercise.
Firstly, the Human operates at around 37.0°C (98.6°F). This is called the operating temperature. When the temperature of the body drops, the body must work harder (thermoregulate) to raise that temperature back to 98.6°F. It's just thermodynamics though. "Cold water" lowers your body temperature and because humans are warm blooded, your body will modify your metabolism to raise your body temperature: think a biological heater. This requires energy -- in dietary terms, calories:
Discovery Health and Fitness estimates this to be 70 Calories (292 kJ) a day if you drink eight 8-ounce glasses (1.9L) of 0°C ice water. Some fluids will require more energy for your body to raise to body temperature, some will require less.