Hotel rules said it’s not but it’s apparently not a problem as some guests were wearing it at the pool during my stay. In the meantime, hotel rules said shorts are not allowed for dining but they also tolerate it as it’s really hot, it is just common sense to accept people to wear whatever makes them feel more comfortable as long as it doesn’t appear to be offensive or disrespectful. Hotel guests are paying to be happy on vacations not to feel oppressed by rules. :)