Your math is effed up. You didn't do the negative right.
Celsius to Fahrenheit is (Temp x 1.8) + 32
Fahrenheit to Celsius is (Temp - 32) x 1.8
So -36*C is (-36 x 1.8) + 32 = -32.8 F
I think I effed up the F to C formula. I am going off of memory on it and its been about 18 years since I used it. The C to F formula is for sure correct though.