I put in the original sentence and got 122°F first. If I tell it to rewrite and correct C to F I randomly get 20 and 68 every time I ask it.
If I say "recalculate the celcius to farenheit rewriting as little as possible in this sentence: Malawi swelters in record heat with temperatures nearly 20C above average"
Attempt 1. Malawi swelters in record heat with temperatures nearly 36°F above average.
Attempt 2. Malawi swelters in record heat with temperatures nearly 68°F above average.
If I say "recalculate the celcius to farenheit rewriting as little as possible in this sentence: Malawi swelters in record heat with temperatures nearly 20C above average"
Attempt 1. Malawi swelters in record heat with temperatures nearly 36°F above average.
Attempt 2. Malawi swelters in record heat with temperatures nearly 68°F above average.