I carry a full tote into work every night. In addition to allergy meds, caffeine, pain killers, and chewable tums (and all of these have been needed by at least one coworker in addition to times I use them) I have heating pads, kt tape and regular medical tape. Bandaids, saline, gauze, scissors, tweezers and antiseptic creams are in the company's many first aid kits. The only times I have needed more than these, I needed actual doctor's care.
Our medical cabinet at home is actually far more extensive though we have stopped short of John's level of preparation. Mostly of my medical thinking goes into prevention. In case of burns I dig in the fridge for the mustard. Half an our of plain mustard sitting on a burn and not only does it have less blistering, it's pain free and doesn't start hurting again later.