I’m not sure if there’s any good way to tell how well a soft-sided cooler will hold temperature without actually testing it, so here are some considerations that I’ve used:
- How easy it is to clean (both inside and out)? Some have a rubbery or plastic inside that’s easy to wipe down… some also have this on the outside, while others are more fabric-like. Depending on your situation, a fabric outside might be beneficial, as you can wet it down for some evaporative cooling in dryer areas.
- How does it close? Some have zippers, some are Velcro. Test opening and closing it a few times, as some zippers will get stuck, or Velcro may not grab all that well.
- Does it fit what I plan on carrying? If you have a specific container, like a bento box, it should fit that, possibly an ice pack if appropriate for your area, etc.
- It it excessively large or heavy? If it’s too big, it’s a pain to carry, so it’s hilly best to be the size of the stuff you’re carrying
- How durable does it seem? There are times when you might accept a more flimsy bag for size & weight but just be prepared to replace it sooner, but I would still look over if there are any stitching issues at the seams and straps. If it has an inner lining, consider how thick it is, as thinner ones will rip sooner.
- How do you carry it? Some larger ones may have a shoulder strap, smaller ones might have a small carrying strap/handle, or it might assume that you’re going to place it in something else. Also take a note of where the strap is relative to the closure (I had one that pull the Velcro open if you used it), and if your container will be at the proper orientation when using the carrying strap (so it’s less likely to spill)
- Does it fold flat? If you’re going to be returning with an empty bento or similar, this isn’t a consideration, but if you have bagged sandwiches or similar, you may want to collapse it for the return home. You may want a non-folding bag if you tend to carry stuff loose in the bag (not in a separate hard sided container) that might get crushed, such as fruit.
And for the ice packs… if you’re in a really hot place, and you want to eat your food cold, or it will be held for the whole day, then yes. Sometimes you have a food that’s eaten closer to room temperature and is relatively safe (some sandwiches, whole fruit, packaged shelf-stable food), so you may not want one so it warms up slightly by the time you’re going to eat.
