Air quality has reached unhealthy levels, and is hazardous in some parts, after thick smog blanketed six provinces on the islands, according to the National Disaster Management Agency.
“The government’s emergency response has been slow, while people continue to suffer, especially children and the elderly, as a result of the haze,” a group of 12 non-governmental organisations said in an open letter to the president.
The groups urged the government to immediately send medical personnel to treat victims for free and evacuate the most vulnerable citizens to safe locations.
Thousands of schools have been closed on Sumatra in recent days as visibility was reduced to as low as 200 metres.
The dry season in Indonesia is expected to last until October.
The National Disaster Management Agency said last week that fires had destroyed more than 328,000 hectares of plantation and forest across the country this year, mainly in six provinces on Sumatra and Borneo.
The government said it had deployed more than 9,000 personnel and 40 helicopters and aircraft to douse the fires.
Haze has also blanketed parts of Malaysia and forced the closure of more than 400 schools in the Malaysian state of Sarawak on Borneo last week.
The smoke from forest fires in Indonesia often spreads as far as neighbouring Singapore and Thailand.