Is it bad to drink cold water after you spent all night crying? I don't want to sound dumb. What are you supposed to and not supposrd to do.

Cold hides thirst. If somebody has been crying so hard to the point that they are dehydrated (either from tear flow, or drinking fluids and eating) replenishing hydration can be important. Cold water will start to replenish hydration, but it will take away thirst, sometimes too quickly. Room temperature water does not artificially hide thirst. Be sure to address the causes of the crying and feel better soon.