Cass and Shannon enter the labyrinth of pitch black caves, where they encounter rabid bats and deep drop-offs.

In the Everglades, Amber had two different parasites that caused her to be medically taken out of the challenge. Watch her explain her painful recovery and how she feels about her challenge.

Cass and Shannon meet for the first time - naked in Belize - as they begin their 21-day survival challenge.

Cass is sick and tired of ticks plaguing him, especially in his eye lids and around his "pee hole."

Michelle and Jeremy meet in the oppressively humid swamps of Louisiana and make a naked pact to make it through 21 days.

Cass and Shannon run across an ancient cave system during their 21-day survival challenge in Belize.

Hand drilling is a tedious method of making fire. Right off the bat, Kristin learns how hard it is - but that doesn’t stop her from creating her first fire!

Tawny and Julio acknowledge the awkwardness of meeting a stranger naked for the first time as they get naked in Florida.

Working as a naturalist on a nature preserve, Melissa has not yet truly left the wilderness since her time in the Amazon. She will soon be working for a nature expedition company and hosting her own nature boot camp to teach others how to survive in

Water is scarce and the hot sun makes energy levels difficult to maintain.

Sarah from the "Lost At Sea" challenge in Exumas checks in from her sailboat in Hawaii. Still positive and upbeat, Sarah continues to adventure the world whether it be by land of sea.

Kristin is inspired by all the uses, both practical and pretty, she’ll have when she masters the art of taking fibers to make cordage.

The nights are long and cold during the 21-Day survival challenge. One of the best ways to combat the elements is to snuggle, but not all partners are comfortable.

During Kim's casting tape for Naked And Afraid, she describes what her ideal partner would be to balance her personality during the 21 Day challenge.

Five days into the Naked And Afraid challenge, Julio claims he has no hunger. At the same time, Tawny experiences hunger pains and continues to hunt for the team.

Forget pirates and voodoo curses, the scariest thing about Louisiana might just be the mosquitos. Will Michelle be able to make it through 21 days of biting torture?