On a sunny morning in June, I walked to work with a quadruped robot beside me. I've never gotten more attention from strangers. A bunch of people snapped pictures of my robot dog. Several people asked me questions. Was it mine? (Yes.) Did I build it? (No.) Was it being used for surveillance? (No.)

Biological dogs kept a safe distance from my mechanical companion. Some growled or barked at it. Children were fascinated. I paused and had it do tricks for several of them: “shake hands,” do a handstand, or leap into the air.

I live in a leafy Washington, DC, neighborhood called Mount Pleasant. The neighborhood lives up to its name, so my morning commute is mostly downhill. My robot companion, manufactured by the Chinese company Unitree, walked the two miles to my office near the White House with battery capacity to spare. I recharged the battery during the workday, but it still struggled on the afternoon walk home. We were now mostly walking uphill, and the temperature had risen to 87°F (30°C). The robot's steps seemed increasingly labored as the path got steeper.

As I entered my own neighborhood, I glanced at two indicators in the corner of my phone screen. One showed that the robot's battery was at 5 percent—dangerously close to empty. The other showed the internal temperature was 84°C (183°F). We were within sight of my front door when the robot suddenly collapsed. I'm not sure if it ran out of power or overheated, but either way it didn't shut down gracefully—it rolled onto its back with its legs in the air.