A warning has been issued by one of the country's county councils after it received worrying reports of children getting sick after swimming at popular bathing spots.
Leitrim County Council issued advice on water quality in lakes and rivers yesterday as people enjoy a dip during the heatwave.
People are advised to avoid swimming or bathing in areas where there is an algal bloom or scum in the water or near to the shore.
The council said it has "received reports that children have become ill after swimming" in Acres Lake and at Cormongan near Drumshanbo.
These are undesignated bathing areas according to the authority, who "advises strongly against bathing in such waters".
In a subsequent alert issued today, Leitrim County Council further reiterated its message on water quality in lakes during the extreme temperatures.
The public were once again warned not to swim in non-designated bathing areas, while swimming and contact with waters where there is an algal bloom or scum in the water or near to the shore should be avoided.
It said in a statement: "Leitrim County Council advises against bathing in Marinas or Harbours that are shared with boats.
"Incidences of illness that arise after bathing in such areas should be reported to the HSE.
"The HSE has advised us to inform parents of children who become sick following swimming to see their family doctor or GP.
"Where the GP suspects there may be a general public health concern, the GP will notify the Public Health Section of the HSE about such incidents."
it is advised that dogs should also be kept out of such waters.
Algae are naturally found in many lakes in Ireland and these may multiply significantly particularly during warm weather conditions.
This can then result in the water becoming discoloured and a scum-like surface appearing on top of the water.
While algal bloom or scum is not always harmful, a number of illnesses can result from contact with the affected water such as vomiting and diarrhoea, skin rashes or eye irritation.
It can also be harmful to animals, which is why dogs are advised to steer clear of the algae-enriched waters.
