Hackers targeted refrigeration systems at three French blood banks, attempting to raise storage temperatures to extreme levels and destroy vital blood products, the country’s national blood service said on Wednesday. The attack follows a wave of similar incidents at supermarkets across Europe that caused millions of euros in damage.

The French Blood Establishment (EFS) said the cyberattack compromised monitoring and control systems operated by an external refrigeration supplier, allowing attackers to remotely manipulate temperature and defrosting settings at three plasma storage facilities.

The hackers reportedly attempted to raise the temperature from the normal -30C (-22F) to as high as 110C (230F), well above the boiling point, according to French investigative weekly Le Canard Enchaine, which first reported the incident.

The attack occurred overnight on Monday, when a technician on duty noticed temperatures rising inside the facilities. The EFS said its monitoring and alarm systems helped staff detect the anomalies and secure or relocate the affected blood products before they were damaged.

“No health consequences have been identified and no blood products were lost,” the EFS said, adding that blood collection and distribution services continued uninterrupted.

The affected equipment contained bags of plasma intended for transfusions and pharmaceutical production. Some units were shut down as a precaution, and their contents were transferred to other facilities.

Refrigeration equipment supplier Coolworld confirmed that the attack affected its systems, blaming a vulnerability in a component supplied by another company. Only a limited number of its units were compromised, the company said.

The French Health Ministry and national cybersecurity agency, ANSSI, are investigating the incident. The EFS has also strengthened temperature monitoring across its refrigeration facilities.

The incident comes amid a series of similar attacks on supermarket refrigeration systems across Europe. In October, hackers reportedly disrupted cooling equipment at around 700 French supermarkets, including Carrefour, Intermarche, and Cooperative U stores, forcing retailers to discard large quantities of spoiled food.

A new wave of suspected cyberattacks on Monday affected dozens of supermarkets in Belgium, Sweden, Luxembourg, Ireland, and Estonia. Hackers reportedly activated defrosting mechanisms remotely, with temperature settings at some Swedish stores raised to 50C.

Dutch retailer Ahold Delhaize said on Wednesday that the earlier disruptions could reduce its fourth-quarter sales by as much as €250 million ($281 million) and operating income by up to €100 million.

The authorities have not established whether the incidents are linked, and no group has publicly claimed responsibility.