From The Jedi Path by Daniel Wallace:
Trial of the Flesh Determines a Jedi’s capacity to overcome great pain.
For many Padawans, the Trial of the Flesh is the most difficult of the Knighthood trials. This ordeal will test your ability to overcome great pain, and it may be quite literal.
As a historian, I have studied the Trial of the Flesh in its incarnations throughout the millennia. During the Pius Dea era, the Jedi Order subjected Padawans to torments of cold, cuts, sonic shock, and the application of sustained, low-powered blaster fire in the technique that the smugglers call “the Burning.” Now condemned as barbarism, this practice is best understood as a product of its time. It did, however, crystalize the Trial of the Flesh’s most fundamental principle: divorcing the self from the spirit.
During the most recent war against the Sith, the Council viewed battle as a living expression of the Trial of the Flesh. All Padawans who survived a war injury passed this Trial on the evidence of their scars. Padawans who had defeated a Sith Lord sometimes passed the Trials of the Flesh, Skill, and Courage simultaneously. Far from being a matter of political expediency, these battlefield trials have a long precedent in the Jedi Order. Padawans who lost a limb to cho mok or another Mark of Contact surrendered their flesh to demonstrate their commitment to the Jedi Order.
It is now a different time, and we do not expect Padawans to prove their worth through wounds. The Trial of the Flesh, in fact, is about more than physical agony. The pain of loss is part of your passage from Padawan to Knight, for you are giving up the closest pond you have ever known. As the partnership with your Master is formally dissolved, you may be overwhelmed by feelings of sadness or regret. This is part of your Trial of the Flesh. Think well on the first precept of the Jedi Code: There is no emotion, there is peace.
“Physical pain is one type of test a padawan may face in the Trial of the Flesh.”
This is probably the only Trial I think is more suited to not being tested on the spot. Additionally, it should probably be the easiest to pass. Everyone experiences pain throughout their natural lives, both physical and emotional. I think this should be a trial where a student is asked for examples of times they felt both extreme physical and emotional pain. If a person is out there, living life, they will have more than enough to tell.
Emotional: The loss of a loved one, betrayal, abandonment, ecc.
Physical: Broken bones, sprained limbs (take it from someone who has done both…sprains can hurt SO much worse), severe illness, chronic disease/pain, ecc.