https://consciousnessofsheep.co.uk/2026/06/27/overheated-food-prices/
Across the south of Great Britain, shoppers hoping to find cold drinks, ice cream or chilled food were met with empty shelves this week. Climate change was the proximate reason. But the deeper cause was the failure to heed the many warnings and to invest accordingly. That is, while UK temperatures were the highest on record this week, they were in line with the predictions made by climate scientists over decades. But a lack of investment and outdated infrastructure meant that when the mercury spiked, the supermarkets were unprepared.

The physics is simple enough (and runs contrary to the current flood of scam ‘air conditioner’ advertising) and is the same as in your domestic fridge. A pump and condenser system containing a refrigerant gas is used to pull heat out of the fridge or freezer and to disperse it into the outside air. Reach behind your fridge at home and you will feel the warmth – although, because the area being cooled is small, the heat is manageable. The industrial-scale freezers and fridges used in supermarkets generate far more heat which, in most cases, is dispersed by giant units on the roof… that is, in direct sunlight where the ambient temperature is higher than (in a heatwave) the heat they are trying to disperse. This means that refrigeration is far less efficient and requires far more electricity.

Customer behaviour adds to the problem. In the grip of a heatwave, shoppers are far more likely to be reaching for chilled and frozen goods, meaning that doors are being opened more often. At the same time, supermarket staff are likely to have to restock the shelves more often, again resulting in doors being open when they need to be kept closed. And ironically, as the fridge and freezer units struggle to maintain the cold, they overheat and fail.

Failure is a costly business. And freezer units failed across the UK last week. In just one store – Tesco in Didcot – some £20,000 worth of food had to be thrown out after the freezers shut down:

“In line with Food Safety guidelines, withdrawn food from the supermarket will be converted into animal feed or turned into energy.

“The technical issues seem to be widespread across various supermarkets around the UK, with national reports of empty shelves and broken freezers.”

Across the UK, the cost will have run to several million pounds. And with Britain set to experience more of these ‘heat dome’ weather systems in July and August, the supermarkets – many of which are already struggling to service their debts – are going to take a big financial hit. Not least because hard-pressed customers will be unable to pay more if the supermarkets try to pass the costs on.

Adding to the problem is the way supermarkets responded to carbon reduction targets. As Kieran Howells at Grocery Gazette explains:

“Many larger supermarkets run on complex, energy-intensive refrigeration systems installed across sprawling chilled, frozen and fresh food departments. Older stores, in particular, can be harder to cool efficiently, especially where refrigeration has been retrofitted over time or where buildings were not designed for prolonged high heat.

“The problem is not simply whether a fridge can stay cold, but whether the whole store can keep trading normally when refrigeration, air conditioning, delivery schedules, staff welfare and customer demand are all under strain at once.

“Supermarkets have spent years investing in energy efficiency, carbon reduction and lower-emission refrigeration gases. Those programmes remain essential, particularly given the sector’s exposure to energy costs and sustainability targets. But extreme heat is now testing whether store infrastructure is robust enough to protect availability as well as emissions performance.”

With high temperatures expected to become the norm in years to come, the supermarkets face a choice between doing nothing and writing off millions of pounds of food and drink every time; investing in higher energy refrigeration systems which will be more energy intensive and may reverse carbon emissions reductions; or – to the annoyance of consumers – not stocking and then switching off the freezers in advance of threatened heatwaves. Either way, the supermarkets are set to lose millions of pounds to heatwaves even as food will inevitably rise in price for the rest of us.