According to the Apple Insider report, some Apple Watch SE users in Korea have reported overheating errors. The incident was so serious that some users suffered burns to the wrists and the screens of these Apple Watch SEs were also damaged.
Overheating issue on Apple Watch SE detected just a few days after use. The most recognizable sign is a yellow spot on the screen, which looks like it’s been burned with high heat. Some users also feel a burning sensation in the wrist where the watch is worn. There are also cases that detect while charging.
The overheating problem seems to originate in the area above the display connections, between the Taptic Engine and the Digital Crown. However, it is unclear why this area is overheated so high.
Out of 6 users who reported the incident, 3 users received a refund from Apple. This problem seems to only happen in the Korean market, all 6 cases above are in Korea, and there are no reports of incidents in other markets around the world.
The Apple Watch SE was launched alongside the Apple Watch 6, as a more affordable option for users. It has most of the features of an Apple Watch and has a similar design. However, the Apple Watch SE uses an older processor, no ECG feature, always on display, and blood oxygen measurement.
Reference: phonearena