Water-borne diseases, I'm sure. It's easy for ice to be contaminated; if you go to a part of the world where tap water can't be relied on to be safe, skip the ice.
No, that’s not what he’s referencing. There’s a Chinese belief that cold water makes you sick. Even sanitized, filtered water and ice made from the same. The fear is over the temperature, and is akin to Korea’s fear of electric fans in its irrationality.
I understand, but my guess is that the origin of this belief was from times when cold water would make you sick because it was likely to be contaminated. Given that, it's not irrational at all. If you believe something that increases your survival but you believe it for the wrong reason, it still increases your survival.
I knew a girl from Hong Kong who carried the same belief so it's not just SK.
It's interesting the article didn't mentioned suicide, which I've seen mentioned before as a cause of the myth. The story goes that papers popularised the concept as a way to avoid specifically naming suicide as a cause of death, as a kind of shared understanding while preserving the honour of the families. But a lot of people took it seriously so the idea gained traction.
I consider most, if not all, tap water unsafe and recommend further filtration practices like reverse osmosis.
Secondly, I’ve seen many ice machines throughout my prior work and would strongly recommend avoiding ice cubes as most kitchens don’t clean these properly.
Cultural habits don't necessarily need a well defined cause and effect. The effect in such cases is that people think you are strange for not playing along.
The root of the habit in this case is Chinese medicinal beliefs. Here is a bit of a summary.
"In traditional Chinese medicine (中医, zhōng yī), hot water is used to expel excess cold and humidity from the body, and it is believed to promote blood circulation. This helps detoxify the body and relax the muscles. Cold water supposedly has the opposite effect, slowing organ function and causing painful muscle contractions. Thus, hot water is often touted as the cure for everything from sore throats to stiffness to cramps to fatigue."
Of course, modern people also know that untreated water is not safe. That doesn't explain an aversion to cold bottled water or other drinks though, which while far from absolute is more common than it is in Western countries.
