Carefully pull off the road, stop the vehicle and turn on the hazard warning flashers. Shift the transmission into "P" (automatic transmission) or neutral (manual transmission) and apply the parking brake. Turn off the air conditioner, if used.
If coolant or steam is evaporating from the radiator or from the tank, stop the engine. Wait until the evaporation stops before opening the hood. If the coolant is not boiling or evaporating, leave the engine running and make sure the electric cooling fan is working. If not, turn off the ignition.
Warning! Do not attempt to remove the radiator cap when the engine and radiator are hot. Serious injury could result from hot fluid and steam being ejected under pressure.
After the engine coolant temperature has dropped to normal, check the coolant level in the tank again. If necessary, fill it up to half again. A serious decrease in coolant indicates a leak in the system. It should be checked as soon as possible.
[The original can be found on this resource: toyotaman.ru]