Greece’s first heat wave of the summer is gripping the country, with temperatures climbing past 40 degrees Celsius in several regions since Sunday, and is expected to last through Thursday.

The Health Ministry issued a circular urging the public to watch for symptoms of heat exposure, including severe headache, weakness, exhaustion, fainting, low blood pressure, nausea, vomiting and rapid heartbeat.

Despite the intensity, Greece has fared better than much of Southern and Southwestern Europe, where residents have lined up to buy air conditioners amid extreme heat.

Konstantinos Lagouvardos, research director at the National Observatory of Athens, said this summer resembles 2022, when Greece had a relatively mild season while Western and Southwestern Europe suffered severe heat and wildfires.

A heat wave requires temperatures above 37 degrees Celsius for more than three days, combined with high nighttime lows.