A weak orangutan was found lying on the ground in Ketapang, West Kalimantan on Borneo island.
Indonesia has intensified efforts to contain haze from wildfires across six provinces in Borneo and Sumatra islands.
The fires have destroyed part of the habitat of hundreds of orangutans, risking the survival of the species.
"The situation is quite critical," said Karmele Llano Sanchez, CEO of the wildlife foundation Yayasan Inisiasi Alam Rehabilitasi Indonesia (YIARI).
Sanchez said the fires are "leaving [the orangutans] without any food or water".
The rescued orangutan will be moved to a rehabilitation centre for treatment and, once recovered, released back into the wild.
