2003 Honda S2000 Owner's Manual - Page 226

If Your Engine Overheats 6. Look for any obvious coolant leaks, such as a split radiator hose. Everything is still extremely hot, so use caution. If you find a leak, it must be repaired before you continue driving (see Emergency Towing on page 245 ). 7. If you don't find an obvious leak, check the coolant level in the radiator reserve tank (see page 124 ). If the level is below the MIN mark, add coolant to halfway between the MIN and MAX marks. 8. If there was no coolant in the reserve tank, you may also have to add coolant to the radiator. Let the engine cool down until the reading reaches the middle of the temperature gauge, or lower, before checking the radiator. 9. Using gloves or a large heavy cloth, turn the radiator cap counterclockwise, without pushing down, to the first stop. This releases any remaining pressure in the cooling system. After the pressure releases, push down on the cap and turn it until it comes off. Removing the radiator cap while the engine is hot can cause the coolant to spray out, seriously scalding you. Always let the engine and radiator cool down before removing the radiator cap. 230 Taking Care of the Unexpected