My teen sim got sick on the weekend in summer, I found that annoying as it's the time to do stuff she can't while in school so I sent her out anyway.
When she was trick or treating on spooky day she got to the Shallow house and while talking to June Shallow Dallas came outside and stood near them then started sneezing like crazy so she hot footed out of there fast, but not fast enough as she came down with flu anyway, thanks Dallas
Guess it explains why I saw his sister trick or treating and he stayed at home, my sim had been racking up points and I hadn't spent any yet so I got her simmunity, it seemed alarmingly easy to catch his germs and I had visions of her being sick far too often for my liking, plus as a real life allergy sufferer the last thing I want is my self sim to start too.
