The National Heat Plan will take effect in Limburg, North Brabant, Gelderland and Overijssel on Wednesday, the National Institute for Public Health and the Environment (RIVM) has said. The plan will be extended to the remaining provinces on Thursday.

The heat plan is activated when the Royal Netherlands Meteorological Institute (KNMI) forecasts temperatures of at least 27 degrees Celsius for four consecutive days. Friday is expected to be the hottest day, with temperatures reaching up to 35 degrees and a possible heat index of 9 in parts of the southeast and east. From Saturday, temperatures are expected to gradually fall, with more clouds and occasional showers possible, the KNMI said.

The KNMI introduced its heat stress index in early June as a way for people to assess how taxing the weather may be and whether they should adjust their activities. The index is based on a combination of temperature, humidity, wind speed and solar radiation.

The RIVM is using the heat plan to raise awareness among caregivers of vulnerable people, including older adults and young children. It advises them to ensure they drink enough water, avoid going outside during the hottest part of the day and keep their homes as cool as possible.

This marks the fourth time the heat plan has been activated this year. The first activation came in mid-June, when temperatures of more than 35 degrees Celsius were forecast across the Netherlands.

Organizers of introductory weeks for new students are taking precautions due to the hot weather. Introductory programs are being held this week in Groningen, Leiden and Utrecht. Initiation periods have also started at several student associations, including Amsterdam’s A.S.C./A.V.S.V. student corps.

The organizers of EL CID, Leiden’s student introduction program, have introduced a heat plan for this week. A spokesperson said participants and supervisors will receive water bottles once temperatures reach 26 degrees Celsius. If temperatures rise to 32 degrees, organizers will consider moving events or postponing them until later in the day. “We assess what is needed each day and for each event,” the spokesperson said. Shade canopies have also been installed to help participants stay cool.

During Utrecht’s UIT Week student introduction program, free bottles of water will be distributed at several locations on Wednesday and Thursday. Organizers have also set up shaded areas and sunscreen stations for participants.