Britain’s food supply chain faced significant strain last week as a severe heatwave pushed refrigerated warehouses to their operational limits, raising concerns about the resilience of the country’s cold chain infrastructure amid rising temperatures. Phil Pluck, chief executive of the UK Cold Chain Federation, described the situation as “severe pressure,” highlighting that the industry’s existing systems were ill-equipped to handle sustained extreme heat.

The heatwave, which saw record June temperatures peak at 37.3C on two days, caused widespread refrigeration failures in supermarkets and delivery vehicles, leading to reported breakdowns of freezer units and interruptions in food deliveries. According to Pluck, warehouse roofs reached internal temperatures as high as 50C, challenging their ability to maintain the required storage temperature of -20C. He noted that over half of the country’s temperature-controlled storage facilities are outdated, designed for climate conditions significantly cooler than those experienced in recent years.

The scale of energy consumption also exacerbated the crisis. With some 460 large cold storage warehouses across the nation employing energy equivalent to that used by major metropolitan areas such as Greater Manchester and Leeds combined, the demand placed significant pressure on the electricity grid. The heatwave’s coincidence with a period of low wind generation—despite solar providing about half of the national supply—and calm weather conditions led the National Energy System Operator (Neso) to issue a call for increased generation midweek.

Pluck urged the government to designate the cold chain as critical national infrastructure, advocating for priority emergency grid access for large warehouses and collaborative planning to bolster resilience, including contingency strategies for potential cyberattacks. He also emphasized the need for the industry to modernize aging equipment to meet ongoing climate challenges.

Despite the refrigeration units in major warehouses largely holding, retailers experienced more frequent failures, with freezers in shops under strain due to external heat and increased use by consumers during warm weather. Rupert Ashby, chief executive of the British Frozen Food Federation, explained that many commercial freezers rely on external compressors, which become less efficient as ambient temperatures rise, intensifying operational challenges.

Representatives from Neso and the Energy Networks Association maintained that the electricity supply remained stable throughout the heatwave. However, Pluck revealed that two federation members were denied requests for emergency power beyond their contracted limits, illustrating the tight margins within which the cold chain operated.

Looking ahead, Pluck warned that if temperatures reach 39C or 40C for several days, the sector could face significant breakdowns, underscoring the vulnerability of a system often taken for granted. He also noted that foreign adversaries have identified the cold chain as critical infrastructure, highlighting cybersecurity risks not fully acknowledged by the UK government.

With the temperature having dropped by approximately 10C since the heatwave, the cold chain sector remains on alert as forecasts indicate another rise above 30C in the coming weekend, renewing concerns about the resilience of Britain’s food supply network in the face of climate change.