I am standing in the middle of the University Campus. It is five o’clock or thereabouts, in the heat of August. The temperature must be somewhere in the high twenties centigrade, but I am chilled. A slight breeze riffles my arm hair, evaporating the sweat, and sending shivers through my body.
I am lost; I shouldn’t be. I know I was in the building behind me for the entire afternoon; I know that I’m supposed to be at the Second Cup café on Laurier Street by 5:30 pm. I feel like I have just run a half-marathon. My body wants something badly, but I don’t know what, and I don’t know how to find it.
To understand how I got here, I have to go back a few decades. I am studying physiology at the University of London. I have my head stuck in textbooks and papers every minute I can find. I want to become one of those greats, like Frederick Banting or Charles Best, who discovered insulin, or Bernard Katz, who discovered how neurons communicate with muscles. I have just attended a lecture by Katz. I declare I am in love with those early discoveries; the experiments seem so elegant, so simple. I am also in love with my heroes of the time; those men who experimented on themselves, who dared to ask direct questions of the human body.
I count myself lucky to be studying at a place where experimenting on my fellow students is still possible. We have learned about the Nuremberg Code; about its intent to prevent harm to human research subjects, but we don’t consider that it applies to us. We give little mind to research ethics. We jump on and off steps and measure our heart rate and blood pressure; we drink various salt mixtures and measure urine output; we plunge our arms into ice-cold water; we record brain waves; we make our muscles twitch until they go into spasm; we re-breathe air until we faint.
As I enter my final year, I discover the field of bioenergetics, and my world explodes. Theodor (T.H.) Benzinger becomes my hero, my main man. Like Benzinger, I am fascinated by the way the body produces the heat required to function. Unlike Benzinger, I do not have electrodes implanted in my hypothalamus to record my core temperature. Instead, I waste hours of study time dreaming up experiments that might answer questions about the fire of life. I imagine Benzinger, on the other side of the ocean in Maryland, late at night, sitting at his desk in a pool of light, doing the same. I think we are kindred spirits.
And that’s precisely why I am here, almost four decades later. It is all because of a love affair with T.H. Benzinger. In his younger days, Benzinger studied the physiological effects of high altitude on pilots. In what I consider to be typical Benzinger fashion, he trained as a medical doctor and then as a pilot so that he could carry out measurements on himself as he plunged aircraft from high altitudes back to earth. In my mind, I soared upwards with him on those parabolic flights and felt the terror of descent, aware of his discovery that pilots sometimes die from air bubbles blocking their arteries if the plummet back to earth is too rapid. But, his research into the impact of environmental temperature extremes on the human body interested me the most.
Towards the end of my studies, I became aware of the stories behind the research studies into bioenergetics. I caught rare glimpses of how some of those studies occurred. Scientific papers do not discuss the practical realities of research studies. They certainly do not debate the ethical acceptability of the research. They present the research question, the methods used (often in scant detail), the results obtained, and the implications. So, I only gleaned tidbits of information here and there that made me realize Benzinger had surely been involved with experiments carried out on prisoners of World War II. But, by the time the Nuremberg trials ended in 1947, along with other German scientists he had been spirited out of Germany and encouraged to continue his research in the U.S.
For the past two hours, I have been cycling as hard as I can on a stationary bike at forty degrees centigrade, shut into something resembling a tiny space capsule. Benzinger invented the calorimeter, this sealed chamber used to measure heat gain (or loss) from the body. The idea of placing someone in a “black box” and interrogating the inputs and outputs enthralled me as a young physiologist. Even though I studied human physiology, I carried out many experimental surgeries on anesthetized animals. Those experiments were fascinating, but I was captivated by the idea that knowledge could be deduced from whole, fully conscious organisms. So I find myself, a human research subject in a calorimeter.
The research study is to develop heat stress guidelines for manual workers. It isn’t as simple as it sounds, of course. Reading scientific papers, you sense that there is order and planning to experiments, but rarely does that coincide with the actual sequence of events. The researcher who weighed me and prepared me to enter the calorimeter told me of her difficulties in matching the numbers of participants in each study group. Apparently, she should have finished data collection by now, but she had struggled to recruit subjects in the “fit and over-fifty” category. I learned she is getting married in a few weeks and badly wants to complete the data collection before she takes off on her honeymoon.
To collect my data, I needed to be instrumented. Earlier, I walked into the chamber, trailing all manner of wires that had to be hooked up to the right places. I am wearing a blood pressure cuff around my left upper arm. Every ten minutes, the cuff inflates and then deflates, recording my systolic and diastolic pressure. I am wearing a sports bra and shorts so that the researcher has full access to my skin. I have several electrodes attached to my chest to measure my heart rate and a belt measuring how fast I breathe and how deep. On my right arm and left leg are two small suction cups measuring how much I am sweating.
I am not Benzinger, so I don’t have electrodes in my brain. Instead, I swallowed a thermistor that looks like a pill. The researcher warned me that I must declare it if I need an emergency MRI in the next few days, as the magnetic waves could cause it to burn up inside me. After that time, I’m presuming that my body will have expelled it. I vow to check that carefully. She also asked me to swallow a thermistor attached to a tube as a secondary means of monitoring my core body temperature. I flatly refused. I know myself. The last time I swallowed a tube for a physiology experiment, I emptied the contents of my stomach on my tutor’s feet. I cannot cycle for two hours with a tube down my throat. I was told I could insert it up my nose, and it would automatically feed down the back of my throat. Somehow that seemed worse, so I found myself in the washroom inserting the tube into the other end of my gastrointestinal tract.
I am claustrophobic, so I’ve tried to avoid spelling it out to myself too clearly: shut in a capsule for two hours at 40 degrees centigrade, pedaling as hard as I can against increasing levels of resistance. Instead, I concentrate on Benzinger. How much did he know about those experiments carried out in the concentration camps, the cold tolerance experiments, experiments on the effects of the lack of oxygen, and experiments where the prisoners died in pressure chambers designed to simulate high altitudes. At the end of the war, he was arrested and interrogated. He claimed that he kept away from those studies, that they were against his medical ethics. I turn this over and over in my head as my heart rate increases, and my breathing quickens.
I check in with myself and try a few mental arithmetic challenges. The body is poor at sensing low oxygen levels in the blood, so high-altitude pilots, for example, need to check to ensure that their brains are functioning. I remind myself that I am safe here. The university’s research ethics board has approved the study; I have signed my consent to participate; the risks have been explained to me. There is a medical doctor on hand, should I have a medical crisis; the researcher is just outside the chamber monitoring all my vital signs. Occasionally she checks in through a communication device that allows her to talk to me. I can bail at any point. I don’t, and of course, my pride carries me through.
Then it’s over. The researcher focuses on wrapping up for the day; it’s almost 5 pm. She is young. I want to say she reminds me of myself at that age, a young woman trying to make her mark in a field where so many men have already stamped their boots. But she isn’t like me at all; she is too dispassionate, oblivious to the history behind her work. She weighs me and then barely checks that I am alright before telling me I can go.
So I find myself, in the middle of the University campus, confused. I lost a kilogram of weight as sweat in the two hours I was in the calorimeter. It is that fluid loss that has destabilized my body, and I need to replenish it quickly. A few false turns and I am mercifully at the café. I order the largest-sized lemonade, a pint by my reckoning; at least half my fluid loss. Once I start drinking, I can’t stop. The cold liquid pours down my throat. I should know better. The large quantity of cold lemonade quickly lowers my core body temperature, and my muscles start shivering, desperately trying to keep me warm. Back inside the café, I ask for a similar-sized hot tea. The barista gives me a peculiar look, so I take my mug outside and sit in the sun, trying to re-establish my equilibrium.
Gradually, the fluids restore my body to some sense of normality. I return to thinking about my relationship with Benzinger. Until volunteering as a research subject for this study, I hadn’t thought about his work in ages. I wonder what stories Benzinger told himself after the war, and whether he managed to put his research into a framework that brought him peace. I try again to reconcile my delight in his early work with the cold realities of its possible origins. Finally, I decide I can’t. For now, I content myself with the knowledge that data sampled during my couple of hours in a Benzinger-like calorimeter might eventually contribute to useful guidance for construction workers and others working outside in the heat of the summer.
Gillie Griffin July 2022
With thanks to Michelle April for her careful eyes, and help with the images.
For a glimpse inside the calorimeter see this CBC video from 2018.