heat wave
{'<entity_0>': 'heat wave', '<entity_1>': 'weather'}
[['heat wave', 'subclass of', 'weather']]
A <entity_0>, or heatwave, is a period of excessively hot <entity_1>, which may be accompanied by high humidity, especially in oceanic climate countries. While definitions vary, a <entity_0> is usually measured relative to the usual <entity_1> in the area and relative to normal temperatures for the season. A <entity_0> is considered extreme <entity_1> that can be a natural disaster, and a danger because heat and sunlight may overheat the human body. In the United States, definitions also vary by region; however, a <entity_0> is usually defined as a period of at least two or more days of excessively hot <entity_1>.
['meteorological phenomenon']