WhiteKnight,
Altimeters are calibrated for ISA conditions, and are subject to local Pressure and Temperature deviations from ISA.
With Temperature remaining at ISA, but Pressure varying, it can be simplisticly viewed as the entire atmosphere moving up or down in relation to Sea Level. The pilot can correct for this by adjusting the Altimeter sub-scale to the local QNH (1032 in your example). If the temperature continued to remain at ISA, Indicated Altitude would then be correct at all Altitudes.
If Temperature varies from ISA, it can be simplisticly viewed as the entire atmosphere vertically expanding or shrinking, and the true vertical difference between pressure levels similarly expanding or shrinking. In temperatures above ISA (your example) the atmosphere has expanded, and you will have more actual altitude than indicated (safe), in colder than ISA temperatures, you will have less actual altitude than indicated (unsafe).
In your example, the QNH set at the 3600 ft AMSL departure point has compensated not only for the Pressure variation from standard, but the Temperature deviation from standard (It's now not actually QNH but QFF). This was possible because the actual elevation was known and may be set on the altimeter. As you now climb away from your departure point, the Indicated Altitude is in error in direct proportion to the ratio of the Mean Temperature between yourself and the departure point, and the Mean ISA Temperature between yourself and the departure point, in degrees absolute of course. Here's the Numbers -
Dep = 3600 ft @ QNH 1032 = 3092 Pressure Ht.
Arr = 8050 ft @ QNH 1032 = 7542 Pressure Ht.
Mean Pressure Height = 5317 ft : ISA Temp = 4.466°C = 277.616°A
Actual Mean Temp at ISA + 15°C = 19.466°C = 292.616°A
INDICATED difference in Altitude will then be the Actual Elevation difference (8050 - 3600 = 4450) multiplied by the ISA Mean Temperature, divided by the Actual Mean Temperature. i.e. -
4450 X 277.616 / 292.616 = 4221.9 ft
Actual Indicated Altitude will be 3600+4221.9 = 7821.9 feet.
This is obviously SAFE, if you climbed in cloud to 8050 feet indicated, you would be 228.1 feet ABOVE ground. The opposite is true in colder than ISA conditions, where you have LESS actual Altitude than indicated, an UNSAFE situation.
Upon arrival at your 8050 ft landing point, you would find that you would have to reset your Altimeter to 1040.3 hPa to indicate correct altitude there.
This question MIGHT have come from a Wannabe, but I don't think that this is a Wannabe question, it should stay in the Technical area. Some other posts here suggest that there's still some experienced aviators 'out there' with some Altimetry misconceptions.
Flying from an area of low pressures and/or temperatures to an area of higher pressures and/or temperatures is safe, but NEVER forget the opposite case - FROM HIGH TO LOW, LOOK OUT BELOW !
Old Smokey