Summer is here! What are your tips for picnic coolers?

[rworange]

In another thread about keeping ice cream frozen on a long trip home from the market, I mentioned getting a thermoelectric cooler that plugs into the car.
http://www.amazon.com/gp/search/ref=sr_kk_1?rh=i%3Aaps%2Ck%3Athermoelectric+cooler&keywords=thermoelectric+cooler&ie=UTF8&qid=1275686962

These keep temperatures up to 45 degrees below the the surrounding air. So if it is 80 degrees, the food in the cooler is kept at 35 degrees (you can adjust the temperature upward).

While looking at product reviews, one customer had some terrific tips that it seems would not only apply to thermoelectric coolers, but regular coolers as well
http://www.amazon.com/Koolatron-Voyager-Thermoelectric-Cooler-P-2d27/dp/B000Q73C66/ref=sr_1_1?ie=UTF8&s=home-garden&qid=1275686992&sr=8-1

Basically

1. Cool the cooler before adding food (The colder the better)

For the thermoelectric model that would mean to plug it in first and get the interior cold. For a regular cooler, add some ice an hour or two before adding the food

2. Keep the cooler next to the air conditioning vent in the car

3. Keep the cooler covered with newspaper to keep the sun from directly heating it

There's a recent Chowhound post about thermal cookware. It seems like they work almost like huge thermoses. So you could get some of these and put them in the fridge to cool. Add your food before leaving and put the whole thing in the picnic cooler. While the post is about cooking, it seems these pots could also be used to retain cold as well as heat.

Retained heat cooking - thermal cookware (haybox method)
http://chowhound.chow.com/topics/710290

At to thermoelectric coolers ... I've had mine for six years and love it. You can choose to either keep food hot or cold in these.

I'll probably be getting a new one when I get home next year and some features I will be looking for
- Best ambiate temperature (most are 40 degrees below, some 45)
- Coolers that suck up the least power from a car battery
- Coolers that sense if a car battery is getting low and turn off
- A strap for easy toting (only one current model has wheels
- A hard case so the cooler can be used as a seat
- Large interior capacities (some units use alot of space for cooling elements)

Any other suggestions for making the best use of your picnic cooler ... electric or not

[just_M]

I keep 1/2 gal jugs of water or other beverages in the big freezer for the ice chests this way nothing gets wet. For day outings I freeze 1/2 the bottle of liquid usually in water bottles and then add the other 1/2 still liquid before packing.

[alliedawn_98]

We have one of those Coleman coolers that will keep ice in 90 degree temperatures for several days. We took it camping and put frozen burgers (preformed and frozen by me), frozen chickens, and other items in it. We loaded it on Thursday afternoon and some of the items were still frozen on Sunday. We did drain water and add ice to it a few times just to be safe but it works really well. It does work best if the food going into the cooler is already cold.