Other than those with air-cooled engines, all cars have radiators of some sort. Though these important heat exchangers are generally well-engineered, it should never be forgotten that they often contain boiling, poisonous fluid under extreme pressure. Additionally, many radiators also contain an integrated transmission oil cooler, the contents of which can be a danger in and of themselves.
The most obvious danger associated with radiators is the fluid burn. Because the radiator is part of a closed cooling system which contains fluid that is regularly heated past the boiling point of water, the internal pressures tend to be very great. The fluid in the radiator is kept from boiling by the system's pressure, and suddenly relieving this pressure will result in a sudden and explosive expansion of steam contained within the fluid. This will cause the boiling water to spray upward in a jet-like stream, scalding whatever it touches.
One hospital contributing to the "Journal of Health and Rehabilitation" reported that within a year, it had seen 86 patients suffering from burns associated with radiator fluid. Most burns were on the head and neck and were the result of opening a radiator's cap before the fluid had cooled.
Antifreeze contains a compound known as ethylene glycol, which serves as a lubricant and anti-freezing agent. This organic molecular compound is highly toxic and can be ingested as a side effect of being sprayed with hot coolant. Sadly, some who have prematurely opened radiator caps and have survived the subsequent 2nd degree burns have died of kidney failure due to anti-freeze poisoning.
One side danger of radiators is not to humans, but pets. Ethylene glycol is chemically similar to sugar and has a sweet taste that animals can't resist. Of odd note is that one of the antidotes to anti-freeze poisoning is ethanol, which can be delivered either intravenously or by rapidly ingesting gin, vodka, whiskey or moonshine. Oral delivery is far less sure than intravenous delivery and should only be considered first aid until medical help arrives.
One of the lesser known dangers of radiators is the oil fire. Engine coolant radiators often house a secondary radiator for the transmission fluid. If this coolant system externally ruptures for any reason, it can spray the thin and highly flammable transmission fluid onto hot engine components. Transmission fluid will almost instantly ignite if it comes into contact with an exhaust manifold or catalytic converter.
