Cool, moist, and most of all BREATHING is what gets veggies through hot weather in my trailer.
I don't put them in the fridge at all....and never leave them in plastic bags. Greens of all kinds are wrapped in a damp cloth or paper towel, and loose things like tomatoes/mushroom are put in damp paper bags. Then I put the bundles loosely in a perforated box with a damp towel on top. Using this method I've kept lettuce heads in good condition through the fours days it takes us to consume one, and in temps over 85. (We don't have a/c, by the way)
I keep the box where air circulation is good, and if camped in one spot for a few days, outside in the shade/breeze. I have a little zip-up screened shelter
like this one that protects stuff from bugs.
I learned this trick from a nice lady in a Korean grocery who also taught me how to properly choose green onions from the stack I was timidly helping myself to...
