changing the temperature unit displayed by Conky

I want to make my Conky display the system temperature in Fahrenheit. Researching it myself, I find that I should edit the .conkyrc to add the variable temperature_unit and specify Fahrenheit, not the default Celsius. What's the correct syntax? I haven't found that information yet.

So I opened the conkyrc, and added this at the bottom:
Code:temperature_unit FahrenheitI really had no idea whether that's what it should look like and whether I had to put the line anywhere in particular (that's why I put it at the end). But it evidently isn't, because nothing happened. My Conky is still displaying Celsius.