School authorities, universities, and employers often schedule multiple tests on the same day or week, causing overlapping exam preparation and a dense testing schedule. This multitask learning can be intense, under pressure, and challenge the student's mental and physical perseverance. As a result, it can compromise performance relative to a more 'relaxed' schedule. This paper examines the consequences of multitasking for test scores and cheating in exams and its implications for the ability and gender cognitive gap. The empirical context is high-stakes exit exams in Israel, done at the end of high school. I leverage the empirical setting on two natural experiments to estimate the causal effect of this multitasking learning. The first exploits random variation in the number of weekly tests--the second hinges on days with multiple exams versus days with a single exam. The results show several important regularities. First, the number of exams in a day or a week harms test performance. Second, these effects are evidenced for high and low-ability students, boys and girls. They are much more extensive for immigrants than natives. Third, the harm of such multitasking is larger in tests later in the schedule, daily or weekly. Fourth, these effects are larger in tests of STEM subjects. Fifth, dense exams schedule increase the likelihood of students behaving dishonestly in exams.