Originally Posted by
Rukbat The GPS receiver shouldn't get hot during use, whether the phone is charging or not. (And, as far as the battery is concerned, the GPS receiver is just a resistor, the same as any other part of the phone - it's DC, so .the hardware draws in-phase [or, actually, no phase] current - CPU, wifi receiver, GPS receiver - it's a resistor.)
Nothing in this statement makes any sense. Resistors?

Using the GPS while on charge absolutely CAN and DOES cause a lot of heat.
Using the GPS typically means the display is on for a long time, that uses power and causes heat.
It typically is being used OUTDOORS so the display is brighter. More power/heat.
The GPS receiver obviously uses some power, but that is actually slight.
The PROCESSOR has to crunch numbers to determine where your coordinates are and what map to aquire. More power and heat.
It typically then needs to download maps, the 4G or whatever radio uses power and makes heat.
Then often needs to translate the map vector points into an image. More processor and graphics power and heat.
Toss in some routing math, POI displays, etc., and you have a lot of heat. I have had phones shut down from over heating when charging while running a GPS app on them. It is common.