Bacteria grow most rapidly in the range of temperatures between 4° - 60°F, doubling in number in as little as 20 minutes. In Food Safety and Culinary Arts, this range of temperatures is often called the "Danger Zone."

If you cater food to the public: Never leave food above 4° nor below 60°C over 2 hours in cold countries, or 1 hour in Tropical & Sub-Tropical countries (Pilippines).

It is difficult to keep foods hot or cold without a heat source or cooler when traveling - It is best to cook foods before leaving home, cool them, and transport them cold.