Mallsickness: when glaring/flashing lights, fluorescent colours, horrible music with thumping bass, tangible clouds of transfat, bleeping, clattering, squeaking, scratching, screaming obnoxious children and bewildering crowds of fat noisy adults make you physically unwell (nausea, dizziness, headache, sudden exhaustion) from sensory overload.
Most common in public places: malls, obviously, but also amusement parks, fairgrounds, circuses, cinemas, casinos, fast food restaurants, canteens, parties, clubs, open-plan offices, anywhere within a school (even, or perhaps especially, the goddamn bathrooms)
Symptoms vary individually and onset can range from 5 min. after initial exposure to 3 hours.
Not mentioned in any first aid course...but it should be.
"Ugh, enough. Fifteen minutes in this department store and I'm already mallsick. I need to sit down."
"Hey, look at that guy over there clutching a clothing rack for support! Judging from his pallor and his deer-in-headlights expression, he is having an acute attack of mallsickness. We need to get him out of here, sit him down somewhere quiet, and give him a fruit smoothie."