Had my Phantom 3 standard for a couple of days and it is working great.

However today after being on for about 20 minutes I noticed the entire camera body
very hot to the touch.

Not sure why a camera should get hot but I hope this is normal.

Normally, when the props are turning, the moving air will provide cooling.  If it was sitting still without the props running they yes, it does get hot.  I don't know if the heat buildup is really an issue but out of an abundance of caution I rummaged around and found a little USB powered fan that I can put next to the Phantom while it's just simmering.

Not sure P3S has a poly block in transit behind the gimble if so have you removed it.

Modern cameras do get hot, as the sensor consumes quite a bit of power, and the power consumption increases with resolution and frame rate. Some cameras employ solid state cooling to keep the sensor cool, but it adds weight and additional power consumption to the camera system. As gil says, the camera will be cooled when it is in flight, so it normally would not be a problem.

Hi ,leenanj
The camera should be  on a normal status . Don't worry .

I[b] have the same problem, I like to use the simulator and it doesn't take very long for camera to get quite hot. Of course there won't be any air cooling in simulator mode, so best to probably not use simulator at all.  I do think that's a good idea to put fan on it. Simulator should be designed to use WITHOUT the aircraft, just the RC. Wonder if dji will repair or replace cameras that burn out using simulator. Hope so