Waitrose is preparing to introduce refrigeration systems designed to operate in temperatures of up to 48C as extreme summer heat puts growing pressure on vital supermarket infrastructure.

The John Lewis Partnership-owned grocer is developing technology that combines heat pumps with refrigeration to keep chilled products cold during periods of severe heat.

It is also installing upgraded fridges across its store estate while work on the more advanced equipment continues.

Waitrose retail director Tina Mitchell said: “This summer shows our latest refrigeration technology is more resilient than older equipment, and we’re continuing to accelerate investment across our estate.”

Mitchell said the upgrades would help the supermarket maintain product freshness, improve store reliability and increase energy efficiency as hotter summers become more common.

The investment comes after widespread disruption across the grocery sector during this summer’s many heatwaves, when refrigeration failures left some stores with empty chilled and frozen aisles, causing national headlines.

The Met Office said 2026 was the first year on record that UK temperatures of 35C or above were recorded in May, June and July. A provisional temperature of 37.7C was also recorded in Norfolk on 26 June, breaking the UK’s previous June record.

Waitrose’s latest plans build on a wider programme to modernise its estate. The John Lewis Partnership’s most recent annual report said 28 Waitrose stores received full refrigeration replacements during 2025/26, using lower global-warming-potential, water-cooled systems.

It had also installed heat-pump technology at 69 shops by the end of the financial year.

Rivals are making similar investments as higher temperatures place greater strain on older equipment.

Marks & Spencer is investing in refrigeration designed to operate in temperatures of up to 45C after chief executive Stuart Machin admitted its stores struggled during nine days of extreme heat in June.

Sainsbury’s has also said around 100 stores are set to receive refrigeration upgrades as part of a wider investment worth hundreds of millions of pounds.

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