Yes, I do recall a small sign that stated the A/C would turn off when the balcony door was open but I don't think that sign explained how the prolonged open door impacts other rooms. I could be wrong on that...wish I had taken a picture. Additionally, if the sign wasn't in multiple languages, it could go unnoticed or misunderstood. DH and I discussed the point you make regarding steps management should have taken under the circumstances and we agree, they should have spoken to the guests. That said, the warm room did not ruin our vacation or taint my overall favor of the cruise or MSC...