The lowest temperature a human body can have before it becomes life-threatening is typically around 70°F (21°C) when the body starts showing signs of hypothermia, though severe hypothermia can occur at even slightly higher temperatures. Generally, a core body temperature below 95°F (35°C) is considered hypothermic.
When a person’s core temperature drops significantly, the body begins to lose its ability to function properly. The heart, nervous system, and other organs can be adversely affected. As the temperature falls, a person may experience confusion, lethargy, and eventually loss of consciousness.
It’s important to recognize that individual tolerance can vary, and certain factors—such as age, health conditions, and exposure time—can influence how low a person’s temperature can safely go. In extreme cases, there have been reports of individuals surviving with body temperatures as low as 56.7°F (13.7°C), but such instances are rare and typically involve extraordinary circumstances.