The Frozen-Undead: Ethical Implications of Suspended Animation and Cryonics


With the speed of advancement in research and technology, once unrealistic medical procedures and treatments have now started to become a reality. Suspended animation and cryogenics are some of these futuristically imagined ideas. The idea behind suspended animation involves the process of slowing down an organism’s metabolism to an extremely low rate. This puts the organism in a state called the “frozen-undead.” The goal is to revive them back to a normal, stable condition in the future. This process could potentially provide more time for patients in critical condition who cannot be saved by current medicine. However, there has been growing debate about the research and use of suspended animation and cryonics on human subjects. This paper focuses on the ethical implications of continuing this research and critically examines different viewpoints towards freezing organisms.


Suspended animation is the process of slowing down an organism’s metabolism without causing complete death [1]. In a sense, the organism is in a state of “frozen undead” [2]. The goal of the suspension technique is to successfully revive the organism back to a normal, stable condition in a future time [2]. This process could potentially provide more time for patients in a critical condition who cannot be saved by current medical knowledge or need more time to reach a medical facility [3]. However, a handful of people are choosing to be cryogenically frozen with the hope of resuscitation. Cryogenic freezing is believed to preserve the human body until medical technology has the power to resuscitate. However, cryonics has many ethical implications for society and for individuals. Human rights and the ethical code of engineers will be discussed in this paper in relation to the future of cryonics. The paper will begin by giving a brief background and exploring the current research in this field. With this information, it will be easier to understand the discussion of ethical concerns.


Cryogenics is the study of how materials behave in extreme low temperatures (below -150 ̊ C) [3]. Cryonics, similar to cryogenics, is the technique of storing organisms in low temperature preservation with the hope that resuscitation will be possible in the future [2]. An organism that is preserved this way is said to be in cryonic suspension or suspended animation. Currently, medicine may not have the procedures necessary to cure many diseases. Therefore, with the technique of suspended animation, researchers in this field believe preserving the body could be beneficial in future medicine. The following section will give a brief overview of the cryonic process.

The Cryonic Process

An easy way to understand the concept of cryonics is to think about people who have been rescued after falling into icy lakes. Even though they may have been “frozen” in the water for some time, many people survive because they were put into a type of suspended animation. Similarly, human bodies that are “legally dead” (some brain function active) can be put into suspended animation [4]. Entire human bodies can be frozen using liquid nitrogen. The body is then placed in a metal tank in a cryonic facility. Obviously, to preserve a body for an unknown amount of time is going to be expensive. Currently, the membership fees can be up to $500/month and the preservation can cost up to $150,000 [5]. The neurosuspension of preserving just the brain will be near $50,000 [5]. The brain function is thought to be the most crucial preservation of cryogenic freezing. Many times, people who choose this option will use their life insurance money [2].

Current Research

Although humans have not yet been revived from suspended animation, research using other organisms has been promising. Only a handful of researchers and scientists are testing suspended animation techniques. Animal hibernation seems to be the key in understanding this concept [4]. Most of the research revolves around the idea of human hibernation. This section will discuss the benefits of cryonic research in reference to current experiments. Mark Roth and Peter Rhee are two of the pioneers in cryonic research on the path to human testing. Other university research will also be explored.

Recently, cell biologist Mark Roth has managed to put the world’s first vertebrate into an oxygen-deprived state and bring it back to normal development [6]. He found that embryos of the zebra fish Danio rerio can survive for 24 hours in the absence of oxygen [6]. In this state, zebra fish entered a state of suspended animation where cell division, developmental progression, and motility stopped [7]. Their analysis revealed that cell division halted at initial duplication phases of the cell cycle. These results indicate that oxygen deprivation reduces cell cycle progression, which is a fundamental part of development. In another study, Roth reduced the core temperature of mice to about 10 ̊C and later revived them to their normal state [7]. He believes that animals have a “metabolic flexibility” that allows them to respond to environmental or physical stress by lowering their respiration and heartbeat [6]. This is similar to organisms hibernating or going dormant before restoring to their normal state. By reducing the organism’s oxygen to a level below the level that is too low to support life, it is seen that the organism goes into suspension [7]. Humans might respond to this extreme oxygen level in the same way.
Defense Advanced Research Projects Agency (DARPA) has decided to fund over $9 billion to Texas A&M Institute for Preclinical Studies (TIPS) to study the effect of hydrogen sulfide on the human body [8]. Apparently, hydrogen sulfide can block oxygen production in the body. By depriving the body of oxygen, it will go into a state of suspended animation. TIPS is conducting research on swine with several compounds containing hydrogen sulfide [8]. The goal of this study is to find a compound that can prevent excessive blood loss by putting these animals into suspension.

Tucson trauma surgeon Dr. Peter Rhee has gotten approval from the Food and Drug Administration (FDA) for his suspended animation technique for human trials [9]. He has tested his procedure on pigs for the past 20 years by drastically slowing down vital functions in the body [9]. By putting patients into a severe hypothermia, he believes that he can provide people in critical condition more time. This would be extremely useful in the military or in emergency situations where medical help may not be quickly accessible.

Ethical Analysis

As seen by the research above, suspended animation could be beneficial to many patients in need of time. With an increasing number of engineers and scientists pursuing experiments in this field, advancement in cryonics is at a peak. This increase calls into question the ethical implications of this freezing of the human body. These researchers are far from close to resuscitating full human bodies from cryonic freezing. However, people continue to sign up for this option. Thus, it is crucial to consider the ethical implications of this potential technology on society.

Many biomedical engineers are leading the research and testing of suspended animation. Like all fields of work, the field of engineering has certain ethical guidelines that must be followed. Although opinions about religion and philosophy are important to note in this topic, the focus will be on the ethical implications concerning behavior. This section will also discuss human rights and benefits to society.

There are two key ways of thinking about cryonics. The first way involves the idea that suspended animation and resuscitation for humans is not and will never be successful. The other way believes that cryonic technology will be advanced enough to successfully work in the future. Each way of thinking deals with its own set of ethical concerns. The following section will discuss the ethical implications on our society and on individuals based on the two different possibilities.

Cryonics is Not Possible

The most important ethical concern in cryonics is legitimacy, or the lack thereof. People are trusting scientists and engineers to revive their frozen bodies in the future. This is an enormous amount of faith in our advancement of biomedical technologies. What if this assurance of resuscitation is false hope? We have basic human rights that apply to everyone. The right to live is one of the most fundamental human rights. Although patients have the right to choose cryonics, this “false hope” could indirectly alter their choice. For example, an individual decides to choose the option of cryonics in his life insurance policy. Later in his life, he suffers from a coma and does not wake up for months. He is sent to a cryogenic freezing facility and will be kept there for however long that facility exists. However, many patients come back after being in a comatose state for years. The option of cryogenics cannot even begin to promise resuscitation in the future. This patient could have potentially awakened. It is true that awakening after months of being comatose is rare, but medical miracles happen every day. The human body is a mysterious machine that is not fully understood.

In the United Nation’s Universal Declaration of Human Rights, Article 5 explains that no one shall be subjected to torture or inhumane punishment [10]. This is another important concern. Who is to say that patients in suspended animation are rightfully treated? In 50 years, all of that patient’s immediate relatives would be long gone. Even if a facility gives their assurance of proper care for all their patients, how can they be trusted? Recently, there have been allegations against the Alcor cryogenic facility for mistreatment of their frozen human bodies.

The National Society of Professional Engineers has a Code of Ethics that should be followed by all engineers. Their first “Fundamental Canon” states that Engineers shall hold paramount the safety, health, and welfare of the public [11]. By promising the pubic a hope of resuscitation, it seems that this code may be violated to some degree. Is this process beneficial to the society as a whole if suspended animation in humans is not successful? Although research continues to advance in cryonics, most substantial results all pertain to small animals.

Cryonics is Possible

Another group of thinkers believes that cryonics has a very promising future. Cryonics might be developed to the point of successful resuscitation. As exciting as this technology could be for the development of society, it brings a different set of ethical concerns. If cryonics becomes an option of immortality, how will this affect society? Like previously mentioned, the process of going through suspended animation is extremely expensive. As technology advances to make resuscitation possible, the cost is only going to increase. This automatically only give this option to the wealthy. Does that mean the wealthy have an option for immortality while the poor do not [2]? Who gets to play this powerful role? This will not be good for the society as a whole, therefore going against human rights.

Even if this challenge is overcome and everyone can choose the option of cryonics, the implications are still severe. Society will be faced with an overpopulation problem. This could have a direct effect on the amount of resources available [2]. The world is already facing an overpopulation problem, so new generations and old generations will all exist [6]. New ideas will be halted if older generations never die. Essentially, advancement of culture could slow down. For these reasons, cryonics would not be maximizing the most benefit for society as a whole.


The solution to solving these ethical questions is not a simple task. However, rules and regulations are created to protect a certain group of people. In this case, human rights and ethical codes protect the society as a whole. Therefore, it is important to keep them in mind when educating the public about suspended animation and cryogenic freezing.

Current research on suspended animation could be very beneficial to the future of medicine. It could be useful for any patient in critical condition, giving them more time and chance for survival. Suspended animation techniques in the military could help prevent excessive blood loss of soldiers during combat. Therefore, increasing funding towards this research is crucial. However, the concept of cryogenic freezing seems to be premature. Only recently, research has been able to revive small animals and embryos from oxygen deprivation for a few hours. Even minimal human testing has only been newly approved. Although the future of human suspended animation seems promising, it is nowhere near becoming a reality. Therefore, it is not ethical to provide patients with this option. It is possible that cryogenic freezing can be successfully implemented in a few decades.

In conclusion, it is important not to halt technological advancement in society. These advancements improve society, individual wellbeing, and overall conditions of life. However, postponing procedures, such as cryogenic freezing, will prevent unnecessary problems. With the continuation of research in the field of cryonics, society will prosper.

By Anu Rajendran

Works Cited

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[2] W. Leslie, S. Stephen, D. Mike and C. David, “Pro/con ethics debate: When is dead really dead?,” Crit Care, vol. 9, no. 6, pp. 538-542, 2005.

[3] P. Safar, “Suspended animation for delayed resuscitation from prolonged cardiac arrest that is unresuscitable by standard cardiopulmonary-cerebral resuscitation,” Critical care medicine, vol. 28, no. 11, pp. N214-N218, 2000.

[4] K. B. Storey, “Suspended animation: the molecular basis of metabolic depression,” Canadian journal of zoology, vol. 66, no. 1, pp. 124-132, 1988.

[5] M. Darwin, “Alcor Life Extension Foundation,” August 1990. [Online]. Available: . [Accessed 29 March 2013].

[6] P. A. Padilla and R. M. B, “Oxygen deprivation causes suspended animation in the zebrafish embryo,” Proceedings of the National Academy of Sciences, vol. 98, no. 13, pp. 7331-7335, 2001.

[7] E. Blackstone, M. Morrison and M. B. & Roth, “H2S induces a suspended animation-like state in mice,” Science, pp. 518-518, 2005.

[8] J. Oates, “DARPA project seeks immortality, suspended animation,” The Register, 19 July 2011. [Online]. Available: [Accessed 28 March 2013].

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[10] “UN General Assembly Universal Declaration of Human Rights,” 10 December 1948. [Online]. Available:[Accessed 1 April 2013].

[11] National Society of Professional Engineers Code of Ethics, Alexandria: NSPE, 1964.