... may have been well summarised in a quote on the Radio 4 programme "You and Yours" this lunchtime by a gentleman from the Swimming Pools Association about the current boom in swimming pools.
"What about Hot Tubs?"
"Hot tubs are the devil's own swimming pool."
This was known, in almost all its features, to Hieronymous Bosch the artist - 500 years ago.
This is "Tondal's Vision".
(No, I don't like hot tubs very much.)