Temperatures are set to soar to more than 27C in the eastern half of Ireland this week.
Met Éireann has issued a Status Yellow high temperature warning for the province of Leinster and Co Tipperary from 6am on Wednesday to 8am on Friday.
It is forecasting daytime temperatures in excess of 27C and at night-time in excess of 15C.
The service has warned of potential water safety issues due to increased use of beaches, lakes and rivers, uncomfortable sleeping conditions, heat stress and animal welfare issues.
Temperatures are forecast to be cooler in Northern Ireland with a maximum of 25C forecast by the Met Office on Wednesday.
Thursday is expected to be hot and mainly dry while Friday and Saturday are set to be cooler and cloudier with sunny intervals.