The Consumer Product Safety Commission said on Wednesday that it was voluntarily recalling the Ionic smart watch because of more than 100 reports of burn injuries caused by an overheating battery.

More than one million of the devices, which track activity, heart rate and sleep, were sold in the United States from September of last year to December of this year. There were at least 118 reported injuries, including two cases of third-degree burns and four of second-degree burns, due to the overheating of the battery.

The commission said that owners will receive a discount code for select devices after they return their Ionic watch.

The injury reports did not affect the other products of the company.

More than a million of its Force wristbands were recalled after customers complained of skin irritation. The company added an allergy warning about nickel and a size guideline to prevent users from wearing the wristbands too tightly.

Users have reported overheating issues with the Ionic watches.

After agreeing not to use the health and fitness data that Fitbit created to target ads at internet users, Google acquired the company for $2.1 billion in early 2021.