Which is better to drink, warm water or cold water in a plan to lose weight?

Water & wt. loss. You can drink both warm and cold water to help you lose weight. When you restrict caloric intake and exercise you want to remain hydrated typically with cold fluids. Note that if you have a warm beverage ( i.e. broth, herbal tea) before meals, you will delay gastric emptying and hence feel fuller faster when eating the rest of your meal. .
No differnce. Just drink water. The temperature will have no effect on your weight loss. Removing calorie dense drinks like sodas and Frapacuinnos will help the loss. A good balanced diet and exercise are the only true ways to loos weight safely and effectively.