The problem is the simgurus need submissions from pure *vanilla* games. By "pure" I mean remembering to delete localthumbscache.package when removing or changing *any* mods, a step people OFTEN skip. Source: https://sims4.crinrict.com/en/2014/09/delete-cache-files/)
None of the photos of many frozen sims provided seem to be from 'pure' vanilla games. I have started a few clean vanilla games and haven't been able to make the freeze fiesta kick off. Like another poster said, maybe the vanilla chance of it happening it quite low, and certain mods might make sims stand around longer making them freeze. I have also been playing with just certain mods + vanilla trying to see if i can find the culprit but no luck so far.
Vanilla or modded, the *real* problem seems to be what happens when any sim freezes. Everybody rushes outside, does not change their clothes to winter gear, and the chain reaction starts and can kill many additional sims. If this is a problem all they need to do is prioritize getting shelter from the cold ABOVE the urge to witness a death, and add a cooldown to witness death or make it a onetime urge.
I *want* the odd sim to be able to freeze or die of heat in the worst conditions if they get unlucky or do stupid things. I just don't want them taking half my town with them in their quest for a Darwin award.
TLDR If you have pure vanilla saves (no mods and a freshly rebuilt localthumbscache.package after removal of any mods), and everybody is dying, feel free to submit them so the gurus can look into it. If you are running any mod or don't delete your localthumbscache.package after changing/removing mods, what you see may still be the result of a mod, even with the mod itself removed. For example, my own saves with all the deaths had mods running so are invalid. My vanilla saves so far haven't replicated the problem.
Just hoping there isn't some knee-jerk reaction where heat/cold deaths are nerfed like abductions were because some people got nonstop adbuctions purely by chance while others still haven't even seen one.
If you just want protection and don't care to test or have any chance of this happening, LittleMsSam has finished her fix and it's part of her package of Random Bug Fixes on her website: http://littlemssam.de/random-bug-fixes/