This is not so easy to answer, because the cooling time of your backpack depends on several factors:
Insulation: The thicker and higher quality the insulation, the longer the contents will stay cool.
Cooling packs: The size and quality of the cooling packs have a significant influence on the cooling time. Gel packs generally last longer than simple ice cubes.
Outside temperature: The warmer the environment, the faster the rucksack loses its cooling capacity.
Frequency of opening: Each opening lets in warm air and cools the rucksack.
Contents: Large quantities of warm food or drinks require more cooling capacity.
In general, it can be said that for short trips, such as day trips, many cooling backpacks with sufficient cool packs can easily keep the contents cool for several hours. For longer trips, i.e. trips lasting several days, we recommend a cooling rucksack with particularly good insulation and powerful cool packs. We therefore recommend our Petromax cooling rucksack, which keeps your drinks and food cold for up to 8 days. So you can also go on long hiking tours without any problems!