Millions of additional visitors are expected in the Eternal City for the largest Catholic pilgrimage event.
"We need men, means and adequate and specific financial resources for Rome to guarantee a rescue and prevention service," said union Secretary General Riccardo Ciofi according to the Roma Today portal. This applies now, but "also in view of the very large anniversary event that will bring an extraordinary number of pilgrims to Rome".
In July alone, the capital's fire brigade counted around 2,000 call-outs just for vegetation and undergrowth fires, three times as many as in the same period last year. The trend continued in August.
According to the union, fewer than 200 people are working per shift, with currently 80 to 100 call-outs per day.
Parts of Italy, including the capital, have been suffering from a heatwave and lack of rain for weeks.
According to the weather service, the current weekend is set to be the hottest of the year so far, with extreme heat warnings in force in nine Italian cities.
The city of Rome is advising its citizens not to leave their homes during the hottest hours of the day.