Rescue operation underway to extract American explorer from deep cave in Turkey after illness

American explorer Mark Dickey became ill while exploring a cave in southern Turkey and requires assistance to exit
Dickey suffered from gastrointestinal bleeding while inside Turkey's Morca cave system over 3,000 feet underground
An international rescue team of over 150 people is working to safely bring Dickey up from the depths of the cave
The extraction is expected to be very complex and could take multiple days to complete due to the cave's terrain
Dickey's condition has been stabilizing after receiving medical assistance, but he is still unable to climb out on his own