The World Health Organization (WHO) advises to: (1) Choose foods processed for safety when purchasing food types which otherwise might not be safe, such as milk (see below); (2) Cook food thoroughly, all food parts must reach at least 70 Celsius and frozen foods such as meat and poultry should be thoroughly thawed before cooking; (3) Eat cooked foods immediately to prevent microbial contamination reaching disease-producing levels; (4) Store foods carefully if you plan to store foods for more than four or five hours, either above 60 Celsius or below 10 Celsius to minimize microbial contamination; (5) Reheat cooked food thoroughly at at least 70 Celsius to kill microbes that may have developed during storage.
In addition, avoid contact between raw foods and cooked foods to prevent cross-contamination, however subtle ([eg] using same kitchen utensil for both without cleaning it first); wash hands repeatedly, wash hands thoroughly before you start preparing food and after every interruption ([eg] toilet, changing nappies, playing with the pet). After preparing raw foods such as fish, meat, or poultry, wash again before handling other foods. Sterilize and cover up any hand infections; keep all kitchen surfaces meticulously clean. Since foods are so easily contaminated, any surface used for food preparation must be kept absolutely clean. Cloths to clean with should be regularly changed and cleaned; protect foods from insect, rodents, and other animals. Store food in tightly sealed containers; use pure water since it is just as important for food preparation as for drinking, and if in doubt about the water supply, boil the water before use.
People in a high risk category should also avoid eating raw fish or shellfish; raw or unpasteurized milk or cheese; soft cheeses; raw or undercooked eggs or foods containing raw or lightly cooked eggs; raw sprouts or unpasteurized fruit vegetable juices.
Food for infants should preferably not be stored at all. Be especially careful with any water used to prepare an infant's meal.