Taking 2 classes during the summer?

I’m considering taking 2 classes during the summer. I am taking intro to statistics but I am also considering another class, preferably online. How was your experience with multiple summer classes?

I took 3 classes one summer. One was an intensive 4 week class on eastern religions that met 2 hours a day, 5 days a week. When that one ended, I took 2 classes at once. One was an in class sophomore level engineering class, and I retook calc based physics 2 online. I liked summer classes because you had homework due every day so you didn’t really get the chance to be behind. I also had the best teacher for the in person course which helped. I also worked 3-5 days a week in a dining court on campus.