Two yang properties appearing simultaneously in one thing. For example:

1. The midday of a day and night, daytime is yang, midday is yang within yang, hence called double yang.
2. Body is hot, pulse is full and large, both symptoms and pulse are yang exuberance, called double yang, indicating the abundance of yang heat.
3. Linking natural climate with human pathological changes, such as summer being yang, summer heat being yang pathogen, thus contracting summer heat in summer can also be called double yang.