Roblox has only recently been ported from the PC onto mobile platforms, such as iOS and Android. However, one issue that people have noticed while playing Roblox on a mobile platform is that their phones start to get hot very quickly. The underlying cause is rather simple - Roblox is a heavily resource-intensive game. Phones are usually passively cooled, meaning that they don't have fans, unlike computers. As such, a phone will get pretty hot once you run intensive programs for too long. This is especially if you play a game like Roblox or one of its games such as Vehicle Simulator. The only solution for this is to take constant breaks every once in a while once your phone starts getting a bit toasty.