Dina Mitchell was sitting reading a book so it is not as if she was doing a major work out. However, she told hacks that: “It was either defective or really mad I was sitting still so long... I do not know. Either way, it burned the heck out of my arm.”

If Fitbits exploded because you did not do enough exercise that would be a selling point. At Fitbit if you go below 10,000 steps a day, it goes boom. Still if that were the case mine would have gone nuclear months ago.

Dina quickly pulled the device off and threw it onto the floor where it continued to smoulder. She had pieces of plastic and rubber removed from the second degree burn to her arm shortly after.

Fitbit has responded to the incident, saying that it is “extremely concerned” and are looking into the issue. It sees “no reason” for people to stop wearing the Flex 2. After all this is the only one we have heard about which kills itself because its owner reads a book.