We tested chilly bins in our refrigeration lab. Packed full with ice and bottles, the chilly bins were left in a temperature-controlled room set at 32°C.

We recorded how long it took the contents to reach 2°C (by which time all the ice had melted), then how long it took the temperature to rise to 8°C (the safe temperature for chilled food).

We tested bins sized between 58 and 70L. The last of the ice in the Techniice Signature 70L clung on for more than four days, while the rest managed about three days. Once all the ice had melted, the contents inside the bins took about a day to heat up to 8°C, showing chilly bins work best as an ice-filled freezer, not a fridge.

In use, we’d expect ice to last longer as temperatures are unlikely to remain as high as our test conditions for so long (in use, keep your chilly bin in the shade to stop it getting unnecessarily hot — there’s a reason so many of these boxes are white). Tip: using salt ice (also known as flake ice) in your chilly bin will keep contents frozen even longer.

Many of the models we tested are available in sizes from 25L to 125L and more, with Icey-Tek selling bins up to a whopping 300L. Larger chilly bins perform better, as they hold more ice, which takes more heat to melt (as long as you fill them right up with ice).