"Safe Food to Go," the USDA's recently issued guide to out-of-home food handling, reminds us that salmonella (a bacteria present in some raw or undercooked food, or food that has come into contact with infected raw food) and staphylococcus aureus (a bacteria sometimes spread by the handling of food) are no strangers to cold weather. Though picnics and outdoor cooking may be months away for most of us, anyone who carries his lunch or transports a meal can benefit from the tips provided therein:

Because staph is normally found on everyone, it's especially important to not only wash your hands before handling food, but to wash everything that comes into contact with the food (such as counter tops, bowls and utensils) between work on each dish. Once transmitted to food and given enough time to produce its toxin, staph will not be destoyed by cooking.

Always keep raw food away from cooked food (i.e., don't prepare the salad on the same cutting board as the meat without washing the board thoroughly). Rather than use your hands for mixing, use a fork.

Never leave food out longer than two hours.

Poultry, eggs, beef and pork -- the prime carriers of salmonella -- should be cooked thoroughly.

Refrigerate packed food the night before, adding foods that might go limp (chips and cookies, for example) the following morning.

If it's not possible to refrigerate your lunch again at the office or school, put something cold inside the container. Insulated coolants work best, but chilled beverages are good substitutes. Sandwiches of coarse-textured bread can be frozen overnight, packed to keep lunch cool and thaw by lunch. Add toppings -- lettuce, tomatoes and spreads -- just before leaving the house. (Cold foods should be kept under 40 degrees.)

Wash lunch containers with soap and hot water daily, and once a week with baking soda to remove odors. Brown-baggers should replace bags daily; never use a soiled or wet bag.

If using a thermos, check the seal to make sure it fits tightly and rinse the cleaned vessel with boiling water prior to filling it. (Hot food should be kept above 140 degrees.)

Discard leftovers. Above all, follow the rule "when in doubt, throw it out."

To obtain a free copy of "Safe Food to Go" write to Consumer Information Center, Pueblo, Colo. 81009 and specify item 597-P.

As suited to an attache' as a brown paper bag, the following Express Lane carryout menu can be assembled within minutes at home. If desired, the sandwich spread can be made the night before. Remember to add the lettuce last.

Express Lane list: yogurt, banana, cheese, whole wheat bread, carrots, raisins, mayonnaise, lettuce. BANANA YOGURT REFRESHER (2 servings)

*1 cup vanilla yogurt

1 banana

Sugar to taste

* Blend ingredients together and pour into a thermos. CHEESE-CARROT-RAISIN SANDWICH TO GO (Makes 2 sandwiches)

2 slices cheese

4 slices whole wheat bread

2 raw carrots, grated

2 tablespoons chopped raisins

1 tablespoon mayonnaise

2 leaves lettuce

*Place cheese slices on each of 2 slices of whole wheat bread. Mix together carrots, raisins and mayonnaise. Place 2 tablespoons of the carrot-raisin mixture on top of each slice of cheese. Top with lettuce and a second slice of bread.

Adapted from "The Natural Lunchbox" by Runa and Victor Zurbel (Holt, Rinehart and Winston, 1984)