[Eremicus]

but I'm wondering how do I get around this when they inevitably ask me to send it back in.

Tell them that they heated up and caught fire, causing superficial burns and as a safety precaution, you Immediately threw them out.

Headsets/headphones can catch fire, Irrespective of their type.

I actually did that before your reply, I said it started smoking and I threw it out. They asked me to send proof of purchase so I made a fake receipt. Hopefully they buy it.