It comes as a sightseer was spotted smoking on Salisbury Crags shortly before the gorse fire ignited.
One eye-witness, who was at the attraction shortly before the fire broke out, said she had seen someone smoking at 6pm next to the gorse bushes.
The Scottish Fire and Rescue Service stressed carelessly discarded cigarettes could be a cause.
Tom Jones Edinburgh: Princes Street Gardens concert stage times, support, setlist and how to get there
Edinburgh Airport: Taxi firms set to bid for control of rank as tender released
West Lothian crime: 'Horrendous' child rapist labelled 'utterly appalling' by judge
West Lothian crime news: A survivor of abuser Malcolm Andrew McDougal has spoken out about her experiences as he is found guilty in court
Newington Fire: Residents forced to find temporary accommodation and road closures still in place
Group Manager Matt Acton said: ”As the warm and dry weather continues, so too does the risk of wildfire.
“Quantities of dead vegetation can provide a plentiful source of fuel for wildfires at this time of year.
“We have seen with the fire last night just how large these fires can become and the significant environmental and economic damage it can cause.
“We are appealing to people to be vigilant and consider their actions – it is crucial that people act safely and responsibly in rural environments and follow the countryside code.
“Just one heat source like a campfire ember or smoking materials can cause it to ignite and if the wind changes direction even the smallest fire can spread uncontrollably and devastate entire hillsides.”