why do we sweat on a hot summer day ?
When body temperature rises on a hot summer day, the sweat gland starts its secretion to keep our body temperature stable. Sweat contains water when this water evaporates due to high temperature it helps to cool our body. So, when it's hot outside the body sweats and increases blood flow to the skin to cool down faster. Sweating not only helps to manage body temperature but also help to stay hydrated.