Hi, you will probably have to write your own library for this.
Converting British imperial units is not that complicated, because it is just a matter of multiplying a value by the appropriate number. You can obtain them from
http://www.convert-kit.com by entering a couple of values.
For temperatures, it is a bit more tricky. You should take a look at the formulas available at wikipedia (
http://en.wikipedia.org/wiki/Convers...of_temperature). Then, you can also verify your implementation of these by entering test values here:
http://www.convert-kit.com/temperature.html.
Hope it helps!