Quote Originally Posted by CNET
The Nintendo Switch OLED is available to preorder now for $350 and ships in October, and it's already become a hot item. I'd say burning hot, but that might give you the wrong idea. You see, I review TVs for CNET and plenty of folks ask me about burn-in on the OLED TVs I've been recommending for years. Even though it's a lot smaller than a TV, that shiny new 7-inch OLED screen on the Nintendo Switch might spark the same questions. My answer for the Switch is the same as it is for TVs: I'm not worried about burn-in. And based on what I know now, most other prospective buyers shouldn't be either. (...)

Here's Nintendo's response to my request for comment about burn-in:
We've designed the OLED screen to aim for longevity as much as possible, but OLED displays can experience image retention if subjected to static visuals over a long period of time. However, users can take preventative measures to preserve the screen [by] utilizing features included in the Nintendo Switch systems by default, such as auto-brightness function to prevent the screen from getting too bright, and the auto-sleep function to go into 'auto sleep' mode after short periods of time.
Worried about Nintendo Switch OLED burn-in? Read this first