On the big rigs they run heat exchangers. The main cooling system runs a thermostat and regular antifreeze, which is circulated through a water-to-water heat exchanger that circulates outside water around a copper core containing the coolant. That also prevents salt water from getting to the engine(s) on offshore rigs. The heat exchanger has its own water pump for circulation.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!