In 1953, 22-year old Don Zimmer nearly died after being hit in the head by a fastball (in the minor leagues). Zimmer had to undergo brain surgery (where holes were drilled in his skull to relieve the pressure of swelling). He could return to baseball (although he was told his career was over) and he made it to the major leagues the following year. Shortly after this incident, MLB required all hitters to wear a batting helmet.
In 1956, Zimmer was hit in the face by another fastball. That time, he broke his cheekbone.
(Other players in history suffered head injuries as well; some with career-ending skull fractures.)
In this video (from 2016), Cleveland infielder Juan Uribe is hit in the head by a 94-mph (151 km/h) fastball. Thanks to the batting helmet, he did not get injured. (Look at it a few times and notice how little reaction time he has.)
In this video,
from the 2013 playoffs, Juan Uribe hits a two-run home run for the Los Angeles
Dodgers, after trying to bunt twice (to advance the runner on second base to
third, sacrificing himself.)
Watch this video at Youtube.com
Watch this video at Youtube.com
If the batter hits a foul ball in a two-strike count, his turn at bat continues with two strikes. If he bunts the ball foul, however, he is out. The MLB record for most foul balls hit during one at-bat, is 16.
(A hit ball [fair] that rolls or bounces over the foul line, after it has passed first and third base, is still a fair ball.)