A status Red Forest Fire Danger Rating notice has been issued by the Department of Agriculture as the heatwave is set to continue for the coming days.
In a statement, the department said that this status was the highest level and was rare in Ireland.
The notice replaces an Orange High Fire Risk Notice, which had been in effect since last Thursday.
The department said that under the red notice, any ignition "may give rise to rapid and unpredictable wildfire development and spread, particularly in dead grasses, and low moisture shrub fuels like gorse and heather".
Forest owners are advised to implement fire prevention plans, and to be prepared for the likelihood of fire outbreaks on or around their property.
People who work in the farming sector are also advised to exercise caution in relation to the use of machinery around hay meadows.
The department also advises to refrain from the use of fire on cultivated farmland.
Met Éireann has said that Ireland could experience its second highest ever temperature before the week is over.
The highest temperature in Ireland today was recorded at Shannon Airport, which stood at 29.3C.
The highest temperature ever recorded in Ireland was 33.3C in Kilkenny in 1887.
@agriculture_ie issue a Condition Red Forest Fire Danger Rating Notice in advance of further heatwave forecasts for the remainder of the week. Condition Red is the highest level and is rare in Ireland https://t.co/Z2B2vTjeC7 pic.twitter.com/v8a7ihM6uY— Dept Agriculture IRL (@agriculture_ie) June 26, 2018
The high temperatures have caused tar on roads to boil. Sligo County Council has advised motorists that tar is boiling up on the local road between Ballisodare and the R284 Sligo-Ballygawley Road.
The council said that road temperatures in the area are in excess of 44C, and has urged people to proceed with caution as the road is treated by council staff.
Meanwhile, Irish Water has warned that water restrictions will become unavoidable due to demand levels in the Greater Dublin Area.
In a statement, the utility said that water supplies and demand around the country were being monitored.
It said that last summer an average of 565 mega litres of water was used in the Greater Dublin Area per day.
However, last Monday, 609 mega litres of water was used in the Greater Dublin Area. Irish Water says that it can produce 610 million litres of water per day.
Irish Water's Corporate Affairs Manager Kate Gannon said: "If the drought is prolonged, water restrictions would become unavoidable given the trends. Irish Water are appealing to the public to be mindful of their water usage.
"Every effort someone makes in their home or business impacts their neighbour and community."