I have a villain whose superpower is allowing energy flow/interaction between distant objects - in particular, what matters right now is that he can put two objects (or areas) in direct thermal contact at a distance, near-instantly equalizing the temperature of the affected region. (It's worth noting that this isn't thermal contact along an edge but rather between every pair of points in the interior, so the heat doesn't have to slowly travel out of one object and into the other.) I imagine he could use this to link a person and a commonly available heat sink like a section of the ground, nigh-instantly dropping someone's body temp by several tens of degrees, but not nearly to the point of freezing.

This seems like it would probably be fatal one way or another, but I don't know if it would kill immediately or after a few seconds, or even be survivable. Normal deaths due to cold temperatures are very different; they have a hot core and frigid extremities and death occurs after some time, though whether people die from getting too cold or from being cold for too long I don't know. So my question is: What would the effects on the target be? How long would they survive, and as a bonus what would they experience, if anything? What's the actual mechanism of death/point of failure?

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    $\begingroup$ I don't have the knowledge to answer this question properly, but enzymes have an optimal temperature at which they operate. In humans, this optimum temperature is the same as our body temperature. Reducing body temperature means enzyme activity decreases, and since enzymes are vital to everything in our body, that's not good. I couldn't tell you specifically what happens though. $\endgroup$
    – M S
    May 26, 2023 at 16:29
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    $\begingroup$ We know that a drop of 3 degrees in core temperature renders people confused, dis-coordinated etc.. Recovery depends as much on methods of rewarming as anything else. When you say "several tens of degrees"...... This seems like a pure biology question (albeit with worldbuilding context added). When you looked this up, what did your researches show? Much of our policies regarding survival at sea and procedures for revival derive from over 70 years ago. There's a useful chart: Survival in cold water as a starting point for your researches. $\endgroup$ May 26, 2023 at 17:31
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    $\begingroup$ Further: Surgical hypothermic circulatory arrest and Therapeutic hypothermia - again, take note of warming techniques necessary. $\endgroup$ May 26, 2023 at 18:36
  • $\begingroup$ Just a thought: Have you ever put hot water on an ice cube? I think this will cause some interesting effects by thermal expansion/contraction, and maybe even with convection currents. $\endgroup$
    – Atog
    May 26, 2023 at 19:17
  • $\begingroup$ you are a series of chemical reactions, get to cold and they slow down or stop. you die for the same reason a fire dies if it gets too cold. $\endgroup$
    – John
    May 26, 2023 at 20:21

2 Answers 2


The biological term is cold shock.

The average ground temperature on earth is 55°F or around 13°C. If you instantly cooled a human to that temperature a few things would happen.

  1. They would be almost instantly unconscious, although they may gasp and flail for a second based on severe cases of severe cold shock. Neurons can't restore a sufficient action potential or send coherent signals. The few they do get off will trigger tachycardia and gasp reflex if they can fire.

  2. They will die very quickly (minutes) without immediate and severe medical intervention and even then survival chances are low, but not zero. Because the cooling is instantaneous they actually have a better survival chance than normal hypothermia. All process are slowed instantly so most metabolic resources are not depleted but in fact preserved; as long as warming is done properly it is potentially survivable. But the chances of medical premises being set up and ready for this is low in warm weather.

What kills them is essentially not having enough energy available for basic cell metabolism. Too many cellular reactions just grind to a halt. It's like asking why a cake does not bake at room temperature; there is not enough energy for the reactions necessary, You are a series of chemical reactions. Real world hypothermia is actually a fairly poor model here because the human body is large enough it can't change temperature quickly using normal physics (this is why freezing and resuscitation works on small animals but not large ones) so you will not have any direct science. Rapid cold shock is our best model but even that is far form perfect since again the brain and core can only cool down so fast normally. The best model might be cold shock in bacteria, but most bacteria have cold shock response proteins because they are small. Humans have no such protection.

See also:


Ken Zafren, Peter Paal, Hermann Brugger, Raimund Lechner, "Induced Hypothermia to 4.2°C with Neurologically Intact Survival: A Forgotten Case Series", in Wilderness Environ Med, 2020 Sep, vol. 31(3), pp. 367-370, doi: 10.1016/j.wem.2020.02.003, epub 2020 May 29:

The lowest recorded core temperature from which a person with accidental hypothermia has survived neurologically intact is 11.8°C in a 2-y-old boy. The lowest recorded temperature from which an adult has been resuscitated neurologically intact is 13.7°C in a 29-y-old woman. The lowest core temperature with survival from induced hypothermia has been quoted as 9°C. We discovered a case series (n=50) from 1961 in which 5 patients with core temperatures below 11.8°C survived neurologically intact. The lowest core temperature in this group was 4.2°C. The authors also presented cardiovascular and other physiologic data at various core temperatures. The patients in the case series showed a wide variation in individual physiological responses to hypothermia. It is not known whether survival from accidental hypothermia is possible with a core temperature below 11.8°C, but this case series suggests that the lower limit for successful resuscitation may be far lower. We advise against using core temperature alone to decide whether a hypothermic patient in cardiac arrest has a chance of survival.

See also Zafren K., Lechner R., Paal P., Brugger H., Peek G., Darocha T., "Induced Hypothermia as Cold as 3°C in Humans: Forgotten Cases Rediscovered", in High Altitude Medicine & Biology, 2022 Jun, vol. 23(2), pp. 105-113, doi: 10.1089/ham.2021.0144, epub 2022 Jan 28:

Although induced hypothermia for surgery differs from accidental hypothermia, survival from very low temperatures in induced hypothermia provides evidence that humans with accidental hypothermia can be resuscitated successfully from temperatures much lower than 11.8°C. We continue to advise against using core temperature alone to decide if a hypothermic patient in cardiac arrest has a chance of survival.


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