Question

1. why do people sweat when they are hot and shiver when they are cold?

Explanation:

When people are hot, sweating helps cool the body as sweat evaporates, taking heat away. When cold, shivering is muscle contractions that generate heat to warm the body. These are body's ways to maintain a stable internal temperature (homeostasis).

Answer:

Sweating when hot cools via evaporation; shivering when cold generates heat through muscle contractions to maintain body temperature (homeostasis).