Ideas
I’m having the exact same issue as OP. I am a vanilla PC player so I do not play with any mods or CC. I sent my Sims kid to the premade summer camp getaway and within 20 minutes, the camp director and 2 children died from heat stroke when they were in bathing suits and the weather was mild outside - not even hot. I quit without saving then rebooted and tried to send an adult Sim from a different family to the premade fitness getaway. Within a few minutes of my Sim being there, the fitness instructor froze to death indoors - it wasn’t even winter or cold out! When I got the freezing warning, I tried to change her outfit to cold weather, but the same workout outfit she was wearing populated for every outfit category, so that didn’t work. I was so excited for the getaways but so far 2/2 getaway failures which led to wrongful weather-related deaths. None of the Sims were neglected - all had high needs. I hope this glitch gets resolved so I can enjoy the main feature of this EP!