Battery VAMO Hazard? - Need help ASAP

Hi redditors, I recently wasn't paying attention while putting in my battery into my vamo, and realized i put it the opposite way. (button top on the gold spring) It started to get really hot and then I realized my mistake and removed the battery. It has this metallic smell to it now; and its still kind of warm after 10 - 15 minutes. Is it safe to use? Should I wait a while until I use it again?

EDIT: the metallic smell is very apparent in my room