The pair, who were rescued last month in West Kalimantan province, have been released into the wild following medical checkups, and International Animal Rescue is continuing to monitor their health.
The charity, based in Britain, has conducted more than a dozen operations in the past two months to save orang-utans who have strayed out of their natural habitats.
Illegal forest and agricultural fires set to cheaply clear land for Indonesian plantations have for months cloaked South East Asia in thick haze, fouling air across the region, causing many to fall ill and sending diplomatic tensions soaring.
The area is under threat due to rapid deforestation and oil palm development, and much of Indonesia's peatlands are ablaze, releasing carbon dioxide.