I've been doing some reading, and it seem that the trackpads don't actually operate by heat. Not that this helps your situation.
Googling
laptop + cursor + jump returns a surprising number of results, with almost as many theories as to the cause of the problem.
Perhaps you should visit the manufacturer's website or some laptop user's community and see if you can find out if there are others with the same or similar models who are experiencing the same thing you are.
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