@Sunny_Rio If you have temperature effects on sims enabled in your game settings the sim will show signs of discomfort in extreme heat and extreme cold... and it can even be life threatening. This can usually be addressed by modifying their clothing to the appropriate season (hot weather clothing for a heat wave and winter clothing for any time they are outdoors in the winter).
Other environmental factors can also come into play, like if there is a fireplace or fan (which now produce heat/cooling), whether they are wet from rain, etc. There have also been some 'sudden chill' issues which are sometimes bugs (last I knew), with swimming, unless those have been changed in a recent update.
Extreme temperatures can be life-threatening to sims if not dealt with properly and promptly (overheating, freezing to death, and even 'sudden chills' can kill a sim).
Death by Extreme Heat/Cold:
https://www.carls-sims-4-guide.com/death/#seasons
I just googled and see a temperature mod with the title 'Temperature Mod - Mod The Sims' on Google. I'm not allowed to link to it here, and I have no idea about the quality of the mod since I don't use Mods or CC.
SheriGR ☕ – I don’t work for EA
@Sunny_Rio I cannot link to particular mods here, as far as I am understanding it. There are likely nuances of that that I could look into (apologies for not having a more accurate answer).
