Answer
As I am working I will be losing a lot of fluids through sweating. This loss of fluids triggers homeostasis, which in turn, triggers my thirst centers to get me to drink fluids. When I drink a glass of lemonade, I am replenishing the lost fluids and restoring homeostasis. This is negative feedback because I am reversing changes and restoring my body back to the set point.
Work Step by Step
Negative feedback reverses or negates changes done and promotes changes to bring the body back to its set point. If I were sweating profusely, I will also be losing a lot of water. This brings my hydration level below my body's set point. Homeostasis wants my hydration closer to the set point, so it promotes actions to bring that hydration level up. One of those actions is to get me to drink fluids (another action might be to reduce production of urine and increase fluid retention). Drinking a glass of lemonade accomplishes the goal, hydrates me, and helps push my hydration level closer to the set point.
