There are calls for Lidl to pull plans to sell massive pools for the back garden next week.
The pools need up to 7,500 litres of water but the supermarket chain says they don't need to be drained and filled every time they're used.
However Irish Water is urging people to conserve supplies during the heatwave.
Green Party leader Eamon Ryan says the system is already under pressure and he wants Lidl to play its part.
"It's very tempting in this weather to think "God it'd be outside lounging in a pool". But we're running short of water and we need to be careful. We're heading into a long dry spell and we really need to be careful how we use it. So I think Lidl should pull these pools. It's not the right time to be selling them."
A spokersperson for Lidl says the filter which maintains pool cleanliness means you can keep the water in the pool until the end of the summer.