Irish Water Safety say the past week has arguably been one of the most tragic - with eight drowning recorded since the heat wave first began.
The latest case was yesterday evening in Kerry - when a 20-year-old man drowned while swimming in Lough Leane in Killarney.
CEO of Irish Water Safety John Leech said there are two generations who have had little or no experience of swimming in open water - and this is likely to be one of the factors behind the recent deaths.
"Years ago in the 80s and 90s when the water quality started deteriorating the media tended to focus in on the worst possible scenario," he said.
"And Mums and Dads said my children aren't swimming in that so open water swimming became quite unpopular and people started learned to swim in pools
"And lots of people can do five lengths of the pool but they can't to five lengths in cold water."