What do C and H on the thermometer mean?

C and H on the thermometer mean: 1, and "C" is the first letter of the English word "cool", which means cold. "H" is the first letter of the English word "hot", which means hot; 2. The water temperature is the temperature of the coolant. Generally, 70-90 degrees after the engine is turned on is normal. When there is little water in the cooling water tank, the water temperature will be high, and water needs to be added at this time; 3. The automobile water thermometer is generally marked with a dial of 60℃- 120℃ or cold (C)- hot (h). When the automobile engine is working, gasoline will burn in it, releasing a lot of heat, some of which will be discharged through the exhaust pipe and some will be transferred to the engine body. When the engine block temperature is too high, it will cause thermal expansion and damage parts, so it is necessary to use water for circulating cooling.