The most appropriate summer aids, sometimes known as ice chests or chilly boxes, are custom non-woven insulated cooler bags. They're the ultimate supermarket bag, meeting all applicable safety and toxicity requirements. They're made of non-woven polypropylene with insulated polyester fiber and a coated thermal film inner that keeps things warm or cold for hours.

https://www.papachina.com/custom-non-woven-insulated-cooler-bag