How can a person prepare his or her body for an adventure to an extreme environment?

The person can prepare by eating the right food, exercise, hydration of self and condition oneself for the incoming adventure like extreme.  And also the human body systems respond to changes in the external environment, the nervous system and hormones enable us to respond to external changes. 

Everyone has different ways on how to survive in extreme environments, as long as you have the perseverance and willpower to adapt in dangerous situations. First, when you are going on a dessert, expose your body safely to the heat every day and packed some light-colored and loose-fitting clothes as you allies in the transition. If going north, you can adjust to cold through layers of clothes, blankets and shelter. 
Moreover, when you are apt for hiking then increase your daily activity from low intensity to high intensity, doing more exercise or work for longer periods each day and if you are climbing to a higher elevation, be prepared for altitude sickness. Lastly, open your mind to other food sources so you can survive if there were no fast-food chain or food truck.

Active transport. now that i answered your question i wish you can me