The record-breaking heat wave last week in East Antarctica, the coldest region on Earth, saw temperatures surge as much as 85 degrees Fahrenheit above average, bringing readings near freezing and unexpected surface melting instead of the usual sub-zero conditions.

The heat wave adds to a quickly growing list of previously “unthinkable” climate events, and puts an exclamation point on an Austral summer that included brutal heat waves and record-high intensity wildfires in Argentina and Chile and flooding caused by record-setting rains in eastern Australia that killed more than 20 people and left thousands homeless.