There is a rapid CPU load from running Minecraft 1.9(15w31b). If for instance once the official release of Minecraft 1.9 in the near/distant future, someone loads Minecraft version 1.9 on an old and/or significantly under powered computer system, may result in: fire, CPU crash/damage, fan over use(damage to fan), CPU/GPU overheating(resulting in: crash/damage to computer), and/or battery over load. I suggest that this problem be looked into as the overload on this laptop results in rapid heating of the whole computer. This occurs once the program is open(after launcher hides in the system tray).
Amount of Random Access Memory allocated to Minecraft: 476 megabytes.
Amount of Random Access Memory allocated to Java: 500 megabytes.
If your computer is resulting in damaged hardware because of an elevated CPU load, I would recommend you have your computer looked at by a professional, or at the very least cleaned of dust. If a 23% CPU load is sufficient to result in overheating, Minecraft would hardly be to blame for that. That being said, it is common for snapshots to have performance issues since the main focus is typically on new features. The developers put their efforts in performance and bug fixing especially at the end of their snapshot release periods, in order to release stable software once it is no longer experimental.