Usually, a summer course is the equivalent of ONE SEMESTER of an academic subject, so taking a science course over the summer would only partially satisfy Harvard’s recommended high school courses. Keep in mind that a summer course crams 16-weeks of one semester into an 8-10 week summer schedule, so students are required to master that the material in about half the amount of time. That’s not an easy task when taking a science course with a lab.
Most selective colleges (HYPSM et al) want to see high school students – even those interested in Humanities – take one year of physics, one year of chemistry, and one year of biology, and an additional year of one of those subjects at an advanced level. Which of those courses are you planning to skip? And, what are you planning on taking instead?