In Act 3 of Romeo and Juliet, who begs Mercutio to leave the streets of Verona because the Capulets might also be out on the extremely hot day?

Benvolio begs Mercutio to leave the streets of Verona. He
warns that it is hot outside, and when people get hot, tempers flare. Benvolio is
worried that a fight will break out with the Capulets. Both the Montagues and the
Capulets have been warned not to fight. The Prince has declared the death penalty if
they fight.

Of course, Mercutio is strong-willed and ready
for a fight. Ultimately, that is what costs him his life. He is eager to fight. Mercutio
claims Romeo has become weak and submissive. He misunderstands that Romeo is in love.
Furthermore, Mercutio does not realize Romeo has just married a Capulet. Of course,
knowing this may not have calmed Mercutio into submissiveness. Benvolio seems to be the
one with the most sense of the two. He even begs Mercutio to leave
town:

readability="12">

BENVOLIO: I’m begging you, good Mercutio, let’s
call it a day. It’s hot outside, and the Capulets are wandering around. If we bump into
them, we’ll certainly get into a fight. When it’s hot outside, people become angry and
hot-blooded.

Benvolio was
absolutely on target. Moments later, Mercutio and Tybalt fight and Tybalt kills
Mercutio. Of course, he intended his sword for Romeo, but now Mercutio lies
dead.