Change in Physical State. Heat also affects how molecules interact with each other. Heating a solid above a certain temperature will cause it to melt to form a liquid; further heating causes this liquid to boil to form a vapor.
When water is in its solid state (ice) , the water molecules are packed close together preventing it from changing shape. Ice has a very regular pattern with the molecules rigidly apart from one another connected by the hydrogen bonds that form a crystalline lattice.
The answer is yes. The pH of the water changes inversely with the temperature. The more detailed previous answers are also correct. This is the laymen's version. This is the full scale change of liquid water at sea level between freezing and boiling: