I don't understand why this question was closed as lacking focus:
It seemed focused to me -- the OP was asking a single, straightforward question about thermometry: Doesn't the act of measuring temperature change the temperature? Of course, to many of us the answer is obvious. But what is obvious to us is not obvious to beginners. So here we have a beginner who is thinking about thermometry, and it occurs to him -- 'hey, wait a second, aren't I changing the temperature when I use a probe to measure the temperature?' To which the answer is yes, particularly when the heat capacity of the probe is significant relative to that of the object being measured.
I'll add that my answer was also downvoted, so apparently someone thinks I should have done a better job in that department; but I thought it was OK and, more importantly (at least in the OP's view), directly helped the OP's understanding (which was my primary goal).