I’m American, and while I live on the opposite coast from Florida (I live in Southern California), I am VERY familiar with Florida’s weather. People, even Americans, don’t realize that Florida is technically part of “the American South”, which means it is humid, muggy, and disgustingly hot during the summer months, and often well into autumn.
i understand your DS wanted to go for his birthday, but I’m assuming you’re all British and aren’t even remotely used to the grotesquerie that is Florida weather around this time of year.
Not only is it usually somewhere around 30C during the day, it’s so humid that you could probably get your daily hydration intake requirements just by breathing. This means that doing anything feels NASTY, as high temperatures plus high humidity saps your energy, enthusiasm, and your will to live.
To make matters worse, it rains in Florida during the summer/autumn. Like all the time. And thunderstorms and lightning. If you’ve never experienced a rainy day that is high-temperature, it’s awful. People who have never endured “hot day rain” don’t realize that it’s WORSE than “cold day rain”. Your body is like, “wait, the air temperature is warm, I should be drying off” but NOPE, it’s RAINING! Or even if the rain has stopped, the humidity is still 85% so it’s not like you’re going to dry off.
My sister and her friend just got back from a trip to Florida (sister’s friend’s kids live in Miami) and my sister and her friend were physically miserable the whole time. My sister also said they left “just in time”, because apparently a storm is approaching.
I don’t know if you/your DC have been to Florida/the American south/Southeast Asia during the hot and rainy periods, but it’s life-sapping. I would personally never willingly schedule a vacation to those areas during the rainy season.
IMO the situation/your DCs behavior is partially just that your DC ARE being teenagers (despite you insisting they’ve been perfect angels on all previous holidays), but I think a large part of the issue IS that it’s the nasty season in Florida right now, and they probably feel tired, sapped of life and energy, and gross. And being indoors does NOT always help mitigate the effects of a hot and humid climate, but they probably do feel better in the hotel where there’s air conditioning.
You also keep going on about them not going to school - and while I agree that that has no literal bearing on a vacation, it DOES have bearing on their behavior. If they’re homeschooled/have never gone to public school, that does affect their attitude and behavior (i would know; my mother pulled me out of public schooling when I was 13 and it messed me up socially) and you may be seeing new behaviors start to crop up now that they’re on a stressful holiday.