Greetings RKM17,
I am sorry to hear that your EOS R6 camera is overheating. While the camera is powered on and in use, it will generate heat due to use of the sensor and processor. Unlike a Canon DSLR camera to where the sensor only goes on when the picture is taken, mirrorless cameras always need to have the sensor running. The camera's overheat protection may prevent the user from recording video if the camera senses the temperature may be too high to operate in this mode.
Please note that the camera body may absorb more heat and have trouble dissipating heat if used in hot environments where the camera is under direct sunlight. The camera may also have trouble dissipating heat if it's wrapped or covered with materials like a camera cover, and it may have trouble dissipating heat if the camera is near other objects that also give off heat.
For using an external power source, you may click on the following link to view which Canon accessories are compatible with this model.
https://cam.start.canon/en/H002/accessory_0080.html
Regarding non-Canon accessories, we only have information on functionality and compatibility on products manufactured by Canon. Canon does not test third party accessories, so we are unable to confirm whether third party devices are fully compatible.
You may send the EOS R6 camera to our facility for repair if the issue continues to occur.
Canon U.S.A., Inc. has created a new online repair portal that allows you to set up service in a few simple steps. The repair portal gives you the ability to set up service for multiple pieces of equipment at once, and to receive a repair estimate in the majority of cases, depending on your model and issue. The portal also allows you to upload images or videos that will assist us in repairing your product. You can also select how you wish to be notified of the progress of your repair. The portal's service history section allows you to view all services that have been performed on any of your camera or video products since January 7, 2020.
Please follow the link below to access our online repair portal to arrange for service:
https://mycanon.usa.canon.com/signin
Instructions for Accessing and Using the Online Repair Portal.
You will need to access or create your My Canon Account.
If you already have a My Canon Account and your product is already registered, simply click on the “Get Repair Services” link on the left menu and follow the onscreen instructions to arrange for service for your product.
If you have a My Canon Account and your product is not registered, you must register your product first. Click on the “Get Repair Services” link on the left menu, then click on the “Register Product” link on the right. After your product is registered, click on the “Get Repair Service” link on the left menu and follow the onscreen instructions to arrange for service for your product.
If you do not have a My Canon Account, you will need to create one. After you create your account, click on the “Add Product” link to register your first product. After your product is registered, click on the “Get Repair Service” link on the left menu and follow the onscreen instructions to arrange for service for your product.
Once you have completed the repair request, you will have an opportunity to print a copy of the request for your records. This request form will also contain shipping instructions and an address label that you will attach to the outside of your shipping box when mailing your equipment for repair.
