I'm guessing they're used as an ice pack for muscles. Reusable and moulds to your body.

The cans are more of a mystery

That's clearly just a statement put out to make the userbase look like they're unhinged and a blatant attempt to garner some sympathy.

Employees shouldn't be wearing reddit 'swag' outside because it's just incredibly tragic. Corporate branded clothing is for wearing when you're gardening, mucking out the chickens etc.