Nintendo Switch Keeps Overheating

So I was trying to play a game this morning and my Switch immediately started getting very hot and the fan was noticeably louder than normal. Then, the console went into sleep mode without me even pressing the button. I tried again and it slept on me again. I tried cleaning the vents and the side rails but it didn’t seem to fix the problem. If it helps, I’ve had my Switch since March of 2017 (so it’s no longer covered by warranty).