To keep salads and other foods cold when you're cooking and serving out-of-doors, you'll need to do a little bit of planning and know which bowl you'll be putting your salads in ahead of time. Then, take a larger bowl and place the serving bowl in it. Fill both with water and freeze them.
When ready to start serving, bring them out of the freezer early enough to thaw sufficiently, so that you're able to remove the serving bowl. Empty the serving bowl of the ice (keep it for the cooler). Spoon in the salad keeping the serving bowl in the larger one which still has ice, that just fits the serving bowl. This will keep your salad cold and safe for a longer time.
Source: I don't know who taught me this, but I've been using it for years. It works so well. You just need freezer space; although, sometimes that's at a premium around here.
By Julia from Boca Raton, FL