Three foreign countries are sending firefighting planes to Portugal to battle a series of forest fires.
It is the second year Portugal has suffered severe fires
Spain, Italy and Greece are joining Portuguese teams in fighting the fires which have hit the Algarve and Alentejo regions and the Serra da Arrabida mountains south of Lisbon.
At least eight large fires were out of control on Tuesday, said Home Affairs Minister Daniel Sanches.
The country is fighting four times as many fires as last July, he said.
More than 20 outbreaks were reported on Monday.
A huge fire at the Arrabida Natural Park, 50km (30 miles) south of Lisbon, was contained on Tuesday, but officials at the League for Nature Protection said the fire had caused an "irreparable loss for biodiversity and nature".
Plea for help
The international aid effort follows an appeal from Portugal at the weekend.
Spain is sending a Canadair plane, which drops water onto fires, to Alcoutim and Castro
Marim in the Algarve, said officials.
Around 10,000 hectares
(24,710 acres) of forest and agricultural land have already been lost there.
Two Greek planes, meanwhile, will head for the Beja airbase in Alentejo.
Eighteen people died in Portuguese forest fires in the 2003 heat wave and a record 424,000 hectares (1047,727 acres) of forest and bush was lost.
Weather forecasters say current high temperatures will last for most of this week.
Fires have also broken out this week in Spain and France.