While it doesn't work up an actual sweat, the BigDog robot can overheat as it transports loads up to 240 lb. A heat exchanger built into its chest keeps its temperature "normal."

BigDog image courtesy of Boston Dynamics © 2009

Go to the new liquid cooling blog on Lytron Inc.'s and you'll find some details about how an overactive electronic dog keeps its cool.

Boston Dynamics, a high-tech firm in Waltham, Mass., developed BigDog, a 240-lb., 3' long and 24" high non-furry robot designed to climb and run with on four jointed limbs. Not a lap dog, the robotic hound walks, climbs, and runs up to four miles an hour, says the company's web site, which also hosts a video of the wonderkind in action. This version of a family pet sure can tote the big stuff – up to 240 lb – and run up to four miles an hour.

During its test workouts through wooded areas, a flat-tube heat exchanger keeps BigDog from overheating, according to Lytron's blog. And Lytron should know: liquid-cooling exchangers are a specialty of the Woburn, Mass., company. The heat exchanger rests on the front "chest" of the robot.

The blog goes on to explain that flat-tube units typically cool oil, hydraulic fluid or electronics.

BigDog has kept its cool and navigated its terrain successfully enough that its designers have won a $32 million grant from the Pentagon’s Defense Advanced Research Projects Agency to design the next generation BigDog for the United States Marines.