If the heat scale is the diagnosis, this is the pharmacy — and it is a shop, on the street, with a counter and a queue, not a clinic.
The format barely changes: a narrow shopfront, big brass or copper urns, a row of bowls already poured and covered with saucers, a price list, and no seating worth the name. You pay, you drink it where you stand, you leave. Some shops keep a jar of preserved plum on the counter for afterwards, which tells you what the tea tastes like.
廿四味 — twenty-four flavours — is the standard heavy one, a black decoction of however many herbs the shop uses (rarely twenty-four, and the recipe is the shop’s own). 五花茶 is the gentle one, five flowers, drinkable. 雞骨草 is for the liver, which in this system is where the heat collects.
Why it counts as Cantonese and not Chinese
Because of the geography. Herbal medicine is common to the whole civilisation; the shop is not. This particular institution — retail, casual, drunk standing up, priced like a coffee, present at street level in ordinary neighbourhoods — is a Guangdong and Hong Kong thing. Go north and the herbs move behind a pharmacy counter or into a hospital.
The reasons usually given are climate and history: a hot, wet, southern place where heatiness is a year-round complaint rather than a seasonal one, and a merchant culture that turned the remedy into a product early. Wong Lo Kat, the most famous name, has been selling it since the nineteenth century and now exists mostly as a sweet canned drink, which is its own small tragedy.
What it tells you about the culture
That the correction is public and casual. There is no appointment, no diagnosis by a professional, no privacy. You decide for yourself that you’re heaty, walk in, and drink something unpleasant in front of strangers who are doing the same. Health, here, is not a private medical matter — it’s an everyday piece of household maintenance, like getting a haircut, and the street is set up to provide it.