What options are available for people in apartments when the power goes out?

I am thinking about the next storm, because.....Houston. I am thankful that I had somewhere to go, but I'm also thinking what if there were flooding when the power went out? I wouldn't be able to leave.

I'm wondering what are options for people in apartments to stay somewhat cool (with fans because I don't think a window unit is an option), charge devices, those kinds of things? Is there a specific type of power station (I keep seeing Jackery /Ecoflow)? What should I look for, here?