The Coastguard has issued a fresh safety warning for those taking to the water during the continued heatwave.
Among the advice is to wear a personal floatation device and never swim alone, or after drinking alcohol.
Five people have drowned in the past week, including a 19-year-old man in a Co Roscommon lake last night and a 10-year-old boy in Youghal in east Cork yesterday.
Johnm Leech, Chief Executive of Irish Water Safety, appealed to swimmers to take extreme care.
"Fresh water is more dangerous than salt water, that's the first thing we'd say," he explained.
We'd ask everyone to swim on lifeguarded waterways, and there's a whole list of them with all the hours that lifeguards are on duty [online]."
"The lifeguards are professional, they're very good at their jobs … they will keep your family safe."