There is a Korean saying that not even a dog catches a summer cold — used partly to tease the sufferer, partly to say that a summer cold is a nasty and badly timed thing. Underneath the teasing there is a piece of physiology worth taking seriously. This article is about the summer cold in Korean medicine, and about a distinction most people miss: air conditioning and cold food are both “cold”, and they do opposite things to different constitutions.
In Summary
- KTM attributes colds to cold pathogenic influence (한사 寒邪) entering the body. Like viruses, it is always around; what changes is whether you are open to it.
- In summer the body moves its yang(＂陽) energy out to the skin surface, which concentrates the defence exactly where an invasion would arrive.
- So a cold that tries to enter is turned back at the skin. That is the physiology behind the saying.
- Catching one anyway usually means artificial cold — air conditioning and cold food — has undermined that defence.
- The key distinction: air conditioning acts on the surface, cold food acts on the interior. They are not interchangeable.
- Air conditioning suits Pulmotonia, Colonotonia, Renotonia and Vesicotonia — it gathers over-floating qi back inward.
- Air conditioning causes trouble for Hepatonia, Cholecystonia, Pancreotonia and Gastrotonia — it shuts the pores and traps heat that needs to leave. This is the classic air-conditioning sickness picture: stifling inside, chilled outside.
- Cold food runs the other way. It suits the Wood and Earth types, and destabilises the Water types.
What Summer Does to the Body
Korean Traditional Medicine (KTM), the traditional healing system of Korea also known as Hanbang (한방), treats a cold as the entry of cold pathogenic influence (한사 寒邪) into the body. That influence is always present in the environment, much as viruses are. The question is what state the body is in when it meets one.
And the body is in a different state in each season. In summer, adapting to the heat, the warm and active energy of the body — yang(＂陽) qi — moves outward and concentrates at the skin surface. Functionally that means the defence has massed at the border.
In that configuration, cold arriving from outside runs into strong yang at the skin and cannot get deep. It is repelled at surface level and that is the end of it. Which is why, if the season is allowed to run its own course, summer colds should be uncommon — and why the saying exists.
So Why Do People Catch Them?
KTM locates the answer in cold that is artificial rather than seasonal: cold food and air conditioning.
Old texts already warned that sitting too long in a mountain stream in summer, or eating too much cold food, invites illness. The mechanism is the same in a modern building. These things damage the yang that is supposed to be massed at the surface, and open a route inward for cold that would otherwise have been turned away.
Which reframes the summer cold usefully. It is less a matter of bad luck than a signal that something in the daily routine dismantled the season’s own defence.
The Distinction That Matters: Surface Cold and Interior Cold
Here is the part that gets flattened when people just say avoid cold things in summer.
Air conditioning acts on the surface. Cold food acts on the interior. Because ECM’s constitutions differ in where their heat sits, the same person can need one and not the other.
Air conditioning
Cold air blows cold in from outside and drives the qi massed at the skin back into the body.
- Helpful for Pulmotonia, Colonotonia, Renotonia and Vesicotonia. These constitutions carry their qi toward the exterior and feel the heat for that reason. Air conditioning gathers the over-floating energy back inward and helps restore balance.
- A problem for Hepatonia, Cholecystonia, Pancreotonia and Gastrotonia. These types feel the heat because heat is trapped inside and cannot get out. Cold air closes the pores of the skin and shuts the exit. The result is the familiar air-conditioning sickness: stifling within, chilled without.
Cold food
Cold food cools the interior directly, so the grouping changes.
- Helpful for Hepatonia, Cholecystonia, Pancreotonia and Gastrotonia — the constitutions with interior heat. Cooling food brings that heat down and is a legitimate way to get through the season. One qualification: Hepatonia and Cholecystonia should moderate the quantity, since their colon tends to run cold even while heat is trapped higher up.
- A problem for Renotonia and Vesicotonia, who are cold inside and hot outside. Cold food gives them an upset stomach or chills the interior further, and the balance tips.
Reading It Together
Put the two lists side by side and the practical upshot is clear enough to act on.
A Vesicotonia is often better off in the air conditioning and worse off with the iced drink. A Pancreotonia is often the reverse — the cold drink helps, the fan blowing directly on them does not. Telling both of them to avoid the cold in summer gives one of them the wrong instruction and half of the other’s.
This is the same theme that runs through the rest of this site. Cold is not one thing, and neither is heat; what matters is where in the body it acts, and which direction that particular constitution needed to go.
Summary
Summer arranges the body’s defences at the skin, which is why the season should protect you rather than expose you. A summer cold is usually evidence that artificial cold got in the way of that arrangement — and which kind of artificial cold you need to watch depends on whether your heat sits at the surface or is stuck inside.
Rather than bad luck, treat it as an occasion to look at the room you sit in and what you have been drinking.
Related: The Autonomic Divide in ECM · Spring Fatigue and Constitution
