If you have electrical supply issues, then a UPS will let you ride through such outages.
The battery capability may need to only last you 5 minutes so you can gracefully shut down.
As it is now, there is a possibility that a disk segment may not get properly updated if the failure occurs at a critical point in the update process. One thing you can do is to disable disk write cacheing. You will pay a performance hit for that.
https://www.tenforums.com/tutorials/21904-enable-disable-disk-write-caching-windows-10-a.html
You can also run chkdsk which will scan for missing links and correct them.
I think it is never wise to handle a pc while it is running.
But, if a case side is easy to open, your risk is minimal.
If you are having heat issues, take the covers off before you test.
If that resolves the issue, look to case cooling solutions.
I would not worry about dust for a one time test.
Longer term, you want good front air intake that is filtered.
What is the make/model of your case?
What do you have inside that needs to be cooled?
What is your graphics card and cpu cooler?