help and assistance

[Zaid]

i am looking for a circuit to measure difference in temperature (+ or -) on the human body.
the distance is between two thermal sensors is about 5 cm, and the reading range is between 0 -50 Celsius.
i have a circuit but i need to make it more sensible. i was thinking of adding differential amplifier.
any one has got an idea of how to improve that
many thank in advanced