Hi Luispipeval,
I have worked with A119 in high altitude and temperatures and let me tell you that the performances of this helicopter has been always excellent.
There are plenty of A119s used in Spain and Chile for firefighting and all crews are really happy with it.
As far as you know the temperatures in summer at south Spain are around 40ºC, some time higher and the performances are really good.
Let me see If I can scan the performances charts and send you.
Cheers!