Met Eireann has issued a status yellow weather warning for high temperatures that will persist until Friday.
The warning states that daytime temperatures of 27 to 30 degrees are expected throughout the week.
I’m the evening times it will remain hit and humid, with the mercury not falling below 17 to 20 degrees.
The warning covers all of Ireland from 1pm on Tuesday afternoon, until 9am Friday morning.
The heatwave has led to dangerously dry conditions, with the Department of Agriculture issuing a warning for a high risk of forest fires this week.