I received my Pro3 today and left the controller & drone on for firmware update on kitchen counter (75°F)
The drone (standard) battery got really hot.
The firm update failed.
I let it cool down and completed the update later.

I notice now that whenever I start the drone on the counter, its battery heats up quickly.
5 minutes, it goes from 21 to 32C in 5 minutes at rest on the counter.
I have never flown it.
Maybe it needs cooling air of flight?

I did charge the drone & controller batteries right after opening the box.
Drone said 100%, after an hour on a standard wall charger.
It did not heat up during charge.

Correct: The Mini 3 Pro does not have active cooling, and thus, it may heat up when not in flight. I am using a small ventilator that I put in front of the drone when performing any non-flight actions. Never had any issues.

It's all okay like that, it's like that with every M3P.  

It doesn't have a fan built in...   

It's normal, you can disable the video feed whilst on usb to reduce the heat a bit.

Hi there. Thanks for reaching out and congratulations on your new DJI Mini 3 Pro. In addition to the previously stated comments above, this drone is designed without a built-in fan, which can effectively reduce power consumption to make the flight time longer. Additionally, the new structural design with propellers that have been adjusted for a more aerodynamic flight, which allows the drone to use the wind generated by the propellers to dissipate heat, ensuring good heat dissipation effects during the flight.
If the drone stays in standby mode for a long time, its temperature may continuously rise. DJI Mini 3 Pro comes with a built in temperature control system that the drone can detect the current temperature and decide whether to automatically power off to
prevent overheating.
The regular standby time periods of DJ Mini 3 Pro in the stationary state are as follows (measured in an indoor environment with an ambient temperature of 25C):
During flight: The aircraft is not overheated.
When in standby mode on the ground: Approx. 22 mins.
When updating firmware: Approx. 19 mins (sufficient for 3 times of upgrades: 5 to 6 mins for each update).
Note: If exceeding the standby time, the aircraft may automatically power off to prevent overheat.
We hope this clarifies your concern. Have a nice day!

Perfect; thanks everyone

DaveInTexas Posted at 5-31 04:31
Perfect; thanks everyone

Please reach us back here should you have other concerns. Happy flying!