When I'm using a smaller cooler and I want to make sure what I have in there stays cold, I make sure to put in a Coleman Brite Ice 10 Reusable Ice Pack with my food.
The Brite Ice 10 is a fairly small ice pack that can easily fit into most small coolers and it provides several hours of good cooling ability.
Basics
You know, an ice pack really isn't more than a plastic container with a fluid inside that can be frozen. That's what the Brite Ice 10 Reusable Ice Pack is. It holds about 10 ounces of fluid, which according to Coleman, is non-toxic should the container break. That's not that likely though. I've had my ice pack for years and dropped it and otherwise just exposed to fairly regular use and haven't had any leakage or breakage problems.
The ice pack is not that large and is the shape of a rectangle. It easily fits into my 8-quart cooler that I have. I've also put it in the collapsible travel coolers I have for lunches and stuff like that when I want to make sure what I've got in there stays cold. Sometimes it takes a bit of finagling, but you can fit this ice pack in most places.
Experiences
That frozen 10-ounce block will last for the better part of a day when you've got it in a small cooler and you're not opening and closing the cooler constantly. It'll easily keep stuff cool from the morning to lunchtime, though later than that, and the cooling ability does tend to drop off quite quickly.
These ice packs freeze quite fast, though I honestly just leave them in my freezer and then take them out when I need them so that they are always ready when I need them.
I've used my Brite Ice 10 Ice Pack for several years. Besides a bit of wear and tear around the corners and a few dents from a couple of accidental drops, I haven't had any problems. They seem to be able to withstand just about any regular use. Though I wouldn't be stepping on them or really dropping them from a height, the plastic case is tough, but not indestructible. There's enough play in it that a good hit would probably crack it or tear it.
I've used the Brite Ice 10 Ice Pack in a number of different coolers. Usually in my smaller cooler or lunch container, though I've used it with other ice packs to pack in a bunch of food in a larger cooler. In both cases it works as advertised - the liquid in the pack stays frozen for a while, keeping things surrounding the pack cool for at least several hours, if not more in really well sealed cooler.
I don't really have any reason to complain with this ice pack.
Final Thoughts
If you're looking for a small reusable ice pack for a small cooler or one of those collapsible lunch coolers, the Coleman Brite Ice 10 Reusable Ice Pack might be what you're looking for. It's sturdy, will last a while and works like it should, keeping your food cool.
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