I can't say I know this 100%, but I don't think that it's water that makes you sweat. I think there has to be something that triggers your sweat glands, like activity or worry...But i'm pretty sure water alone won't cause you to sweat.

Ok what happen is my hand and my back they sweat most of the time in school. Even at home sometimes its not hot and I still sweat sometimes.

Not sure does drinking more water would help?