Portable coolers are a summer staple, but using them incorrectly in hot weather can allow bacteria to multiply and raise the risk of food poisoning, experts warn.
Amparo Gamero, a lecturer in health sciences at the Universitat Oberta de Catalunya, said one of the most common mistakes is failing to keep the cooler below 4 degrees Celsius. She said exceeding that temperature promotes the growth of the microorganisms responsible for many of the food poisoning cases that occur during the hottest months of the year.
How to keep food cold throughout the day
Beyond choosing a good portable cooler, experts say the way it is used also affects how well food is preserved. They recommend keeping the cooler in the shade at all times, opening it only when necessary, and using ice packs or pre-frozen water bottles to maintain a low temperature for longer.
The risk rises sharply during heat waves, when outdoor temperatures can easily exceed 30 degrees Celsius. For that reason, experts also advise preparing the cooler just before leaving home and avoiding leaving it inside a car in direct sunlight for extended periods.
The way food is arranged inside the cooler also matters. The most heat-sensitive items should be placed closest to the cold sources, while drinks can go toward the outer areas. Keeping raw foods separate from prepared foods also helps reduce the risk of cross-contamination.
Specialists add that only the food about to be eaten should be taken out at any given moment, leaving everything else inside the cooler for as long as possible to preserve the cold chain.
Foods to avoid
The choice of food matters too. For a day at the beach or in the countryside, experts recommend opting for items that tolerate temperature changes better, such as whole fruit, nuts, canned goods, cured meats, and aged cheeses, as these carry fewer risks after several hours away from home.
Extra caution is advised with homemade mayonnaise, lightly set tortillas, Russian salad, raw fish or seafood, and cream-based desserts, all of which are particularly sensitive to heat and require constant refrigeration to be consumed safely.
Specialists also advise letting home-cooked food cool completely before placing it in the portable cooler, since adding still-warm food can raise the internal temperature and reduce the effectiveness of ice packs.
Proper hygiene of the cooler itself is also important, according to the experts. Removing food residue, moisture, and sand, and disinfecting the cooler before each use, helps prevent cross-contamination and keeps it in good condition.
