At what temperature do all known organisms get killed?

The correct answer is 250°F. At this temperature, most known organisms, including bacteria, viruses, and spores, are effectively killed. It is generally accepted in microbiology and food safety that high-temperature processing, such as sterilization, occurs around this threshold. Exposing organisms to temperatures at or above 250°F ensures that their cellular structures are denatured and that metabolic processes cease, leading to cell death.

This temperature is significantly higher than the boiling point of water (212°F), which can kill many microorganisms but may not eliminate all spores. The options of 180°F and 212°F may be sufficient for certain applications but do not ensure the complete eradication of all microbial life, especially resilient spores. Meanwhile, 300°F is higher than necessary for the purpose of killing all known organisms and is often used in specific industrial processes. Thus, 250°F strikes the right balance for achieving comprehensive sterilization across a wide range of organisms.