Teaching them how to react PROPERLY when their fight or flight response kicks in.
You know, like when your adrenaline levels hit 125 heart beats per minute, and your body goes into its first stage of panic. Things go real weird with the mind at that point. People freeze up or go psycho. Their ability to make rational decisions and think out their subsequent reactions plummets dramatically. Which means everything you just taught them goes right out of the window when a predator jumps in their face. Let's not even talk about when a crisis drives you to 150bpm or higher.
You can't teach people how to adapt to this inside of a day, and without being able to adapt to that 125 bpm level 1 panic mode, anything you teach them is fairly useless.