Firefighters have been battling several major gorse fires in counties Fermanagh and Tyrone.
The Northern Ireland Fire Service said the blazes appeared to have been started deliberately.
The largest fires were brought under control on Tuesday night in Belleek, Plumbridge and Coalisland.
A NIFRS spokesperson said: “It is most important that we all play our part in protecting our communities during this national emergency, and to ensure that we do not add unnecessary pressures to the emergency services.
“The public are also reminded that deliberate setting of wildfires is a criminal offence and if you see anyone setting a fire you should call the PSNI immediately,” they added.
Last year the NIFRS dealt with over 3,000 gorse fires.