The above person is correct. May be there is a leakage of the coolant. Did you have accident on the car before? For short term solution, go to Canadian Tire to buy the coolant (some are pre-mixed, so you don't need to mix with water), and add them it. Keep an eye on the coolant level. Better don't let it over heat otherwise you will burn the engine out then your car is dead. You need to take the car to a garage to fix it.