In general, it’s best to stop any device from overheating as soon as possible to avoid causing temporary or permanent damage, but how do you know if your Roku is overheating? The most straightforward method may be if your Roku itself is hot to the touch, especially if your device is not being used or if the components have been affected enough that its lighting indicators are no longer functioning. Advertisement
But even if the device isn’t physically hot yet to touch, it may have already exceeded its ideal operating temperature….

Check out the original article: [Slashgear] Is Your Roku Overheating? Here’s What To Do