Marks & Spencer is investing in refrigeration equipment designed to cope with temperatures as high as 45C, after admitting its stores struggled during the recent UK heatwave.

Chief executive Stuart Machin told shareholders at the retailer’s annual meeting in London that the business had faced pressure during nine days of extreme heat in June.

“There is no doubt we were struggling,” Machin said, adding that M&S was now “assuming it’s going to get hotter”.

The company is understood to be investing in upgraded refrigeration units, including fridges with doors, to help keep products cool as temperatures rise.

The development comes after the UK recorded its hottest June day on record last month, with provisional highs of 37.7C, close to the country’s all-time record of 40.3C set in 2022.

Machin said the hot weather had also driven a surge in demand for ice cream, forcing M&S to order in additional stock after six product lines sold out. One supplier took on 10 extra staff to help meet the uplift in demand.

M&S is not the only retailer facing pressure from higher temperatures. Sainsbury’s chief executive Simon Roberts said last week that staff and suppliers had been “working around the clock” to keep fridges running during the heatwave.

Roberts said Sainsbury’s was investing hundreds of millions of pounds in new refrigeration equipment, with around 100 stores set to receive upgrades.

Retailers are increasingly having to adapt store estates and supply chains for more extreme weather, with refrigeration, energy use and availability of seasonal products becoming greater operational challenges during periods of sustained heat.

Machin also used the annual meeting to reassure M&S shareholders that the retailer was increasing its investment in security measures amid rising retail crime.

He said the business had spent millions of pounds boosting the number of third-party security guards in stores, with staff trained to engage with customers as part of efforts to deter theft.

M&S is also investing in systems to tackle incidents at self-service checkouts, including cases where customers fail to scan and pay for items.

It has been vocal in recent months about the impact of retail crime, with Machin previously calling for tougher action against “brazen, organised, aggressive” offenders.

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