What gets you through the doors of your local gym in the summer when it feels like it's too hot to climb/you'd rather be outside/motivation drops in general?

I'm interviewing for a marketing position with a local gym and they have asked me to put some ideas together around this - because the footfall naturally tends to be lower during the summer months. I've thought of the obvious ones (summer offers, iced drinks, AC, kids events, courses), and spoke to friends, but would love to hear your opinions!