One explanation for your processor’s weakness is that it is a “U” class processor, which means that it is optimised for low power consumption at the expense of high performance.
By using Quick CPU to to improve performance, you are boosting power consumption, which naturally leads to a reasonable temperature rise.
When choosing a processor, it is very important to take this suffix into account, depending on whether you want a powerful processor, an economical processor or other features.
For more information: Intel Core Processor Suffixes