It exists. They often appear throughout the year depending upon how you build your sample.
My favorite part about NESN broadcasts is how much they love talking about short hitting streaks. "Pedroia has hit safely in the past 9 games and it hitting .375 over that time period!" Well, of course his batting average will be probably be higher if he's had at least one hit in each game. When Utley hit safely in 36 games, his average was .405. He still only wound up hitting .309 that year.
The "player is hot" is more theoretical than anything else.