Heatproof sim still burning to death?

Those traits make it so your sims don't get uncomfortable. They can still die from heat and cold.

I think you should check EA Answers HQ to see if anyone has reported it as a bug, and report it yourself if nobody else has. The description for Heatproof says, "Heatproof Sims aren't negatively affected by hot temperatures and enjoy the heat." Death is definitely a "negative" effect.

https://answers.ea.com/t5/Bug-Reports/bd-p/The-Sims-4-Bugs

I've noticed the same with sims being "Chilled", indoors AND with thermostat on. Not sure the spesific sim had "Iceproof", but still, there seems to be something weird going on with temperatures.

Sims should NOT get overheated or freeze with the Heat/Iceproof traits.

Sounds like a bug, I just tested coldproof, had my sim meditate outside until she froze to death reloaded the save bought coldproof and had her meditate until way past the point she had frozen to death

okay but I have temperature effects on Sims unchecked in options and my Sims are still freezing. They are affected by cold. I had two close calls yesterday. Something has messed up since these two Sims have completed both of the new aspirations that came with Snowy Escape. I had no problems before because of my option choices.

"Survival Instinct: These Sims will always escape wildlife attacks unscathed, manage to avoid injury from Skiing, Snowboarding, and Rock Climbing more often than other Sims, and have a natural resistance to inclement weather."

And my Sims almost died. I got a notification about freezing to death and managed to teleport them back to the onsen in time.

Something is messed up.

Yeah, the last update seems to have tuned temperatures (it gets cold inside a sims house if there isn't specifically a thermostat to regulate temp) which is really awesome but it did break the special traits for heat and cold.