The temperature that is too cold for humans is a temperature of 32 F or below without heat.
When the temperature is 32 F or less it is hard for humans to survive although with blankets and keeping yourself warm some you can survive.
I've survived in a cold house during a power outage when the inside temperature was 10 F but I had blankets and used by breath as some heat.
Without blankets or any heat from my breath or body I would've died from the cold.
At minus 30 F a person without being properly dressed for the cold can experience hypothermia in just 10 minutes.
At minus 40 F hypothermia can set in in as little as 5 to 7 minutes.
The average body temperature is 98.6 degrees Fahrenheit.
At an internal temperature of 95 degrees, humans can experience hypothermia, shivering and pale skin.
At 86 degrees, they become unconscious and, at 77 degrees, cardiac arrest can occur.
Most people cannot survive if their core temperature drops to 75 degrees.