I have never heard of any RealSense model overheating to the point where the case is hot to the touch, nor experienced it myself. The camera does have mechanisms for dissipating heat though, so it is certainly not impossible.
For taking a heat measurement with a temperature sensor, another SR300 user who tried this recommended attaching it to one of the fins on the back, which apparently act as a passive cooling fin mechanism. In that case their SR300 was not overheating significantly, they were just interested in a temperature reading to gauge how temperature might affect the sensors.
They apparently didn't share their findings.
This may be one of my stupider ideas, but I'll share anyway. Intel sell an enclosure casing meant for attaching the bare-board version of the R200 camera and a compute board to a drone. Maybe it could be adapted to provide secure housing for a cased SR300 to keep public fingers off it? It's hard to tell without further images than the one provided on the store.
A photo is in the store link above, enlargable by double left-clicking on it.
Also, this useful Intel video shows the inside of the enclosure and how all the components slot together.
This message was posted on behalf of Intel Corporation
Thanks for reaching out!
If your camera is heating to the point you no longer consider it normal behavior, then fill out the form found in https://www.intel.com/content/www/us/en/support/contact-support.html. We will try to help you in there as much as we can.
However, in table 8-4 of the SR300 datasheet (http://www.mouser.com/pdfdocs/intel_realsense_camera_sr300.pdf), you can find the case temperature limits (in still air):
Imaging ASIC 85°C
Infrared Camera 60°C
Color Camera 60°C
Infrared Projector 60°C
I highly suggest you to check this section of the datasheet and to make sure that your camera is not exceeding the temperature limits. If it does so, please stop using the camera and reach us as soon as possible through the form I shared above.
I hope this information helps you,