Hey Obrien.

I think question's author mean relatively high temperature. Please refer to RR The Jet Engine, page 151.

here the question is taking into account the range permissible when using the de-icing system. the range is between 10 degress celcius and -6 degres celcius. Fast cycle is when the temperature is near the 10 degress celcius and low cycle when going below reaching the -6 degrees celciys. Fast cycle takes around 2min and slow cycle around 6min.

When you read Dimky's reference, you see a graph of current versus time. According to that, the current is the same for SLOW and FAST but left on for longer with SLOW. Intuitively you might assume that a FAST cycle uses more current to melt the ice in a shorter time and would therefore be used at low temperatures but that is not the case according to the Jet Engine book and if it's good enough for Rolls Royce, it's good enough for me! :)

This question is confused!
What high air temperatura? Engine? Air intake?

this question is not confused at all Dimky explains it.In my study notes from my acedamy it states that "Fast cycles are used on 10 celsius and slow cycles are used on low temperatures -6-10 Celsius".This is very logical because if you think about it de-icing in low temperatures must be slow and thorough instead of fast because if it was fast deicing woudlnt be effective at all!