The Food Danger Zone: 40°F to 140°F

Food poisoning is miserable at the best of times. When there are no doctors, no clean water and no power, it can be deadly, especially through dehydration in children and older people.

The rule

Bacteria multiply rapidly in the “Danger Zone” between 40°F and 140°F (4°C to 60°C).

• Never leave perishable food out for more than 2 hours: meat, seafood, dairy, cut fruit, some vegetables and cooked leftovers.
• If it’s above 90°F (32°C), such as a hot car, a picnic or a house without air conditioning, the limit is 1 hour.
• Refrigerate perishables within those limits.

When the power is out

• Keep fridge and freezer doors closed as much as possible to hold the cold.
• Eat the most perishable food first, and save canned and dry goods for later.
• Cook only what you’ll eat at one meal, or keep cooked food hot until it’s eaten.
• A thermometer is cheap insurance: you can’t judge temperature, or safety, by smell.

When cooking slowly

Slow methods such as retained-heat (haybox) cooking must bring food to a full boil first, so it starts well above the danger zone and doesn’t linger in it.

For long-term storage without refrigeration, see home canning safety.