Monthly Archives: May 2015

Researcher in the Spotlight May 2015

Professor Mike Tipton is Director of Research for the Department of Sport & Exercise Science at the University of Portsmouth.

What is your research about?

It is about the physiological and pathophysiological responses to extreme environments and the selection, preparation and protection of those who enter such environments accidentally or for work or play. We try to give advice based directly on our applied work, or on the practical application of the findings from our basic research.

How did you come to be working in this field and was this something you always wanted to do?

From an early age, I, like many people, had an interest in how the body works. As a young person I was a swimmer, during my MSc at King’s College, London in 1982 I developed an interest in temperature regulation. As part of the course we visited the Institute of Naval Medicine where Surgeon Commander Frank Golden (Later Surgeon Rear Admiral Golden) was running an experiment on swim failure in cold water. It was the perfect experiment for me; a combination of temperature regulation and swimming – I was hooked. Frank and I then worked together for 32 years until his death last year.

Why is your work important?

I think it is important for different reasons. At one level, we advise industries, the military, elite sportspeople and explorers on how to prepare for extreme environments, protect against these environments and maintain performance in them. As an example, our work identified the need for, and developed the first UK helicopter passenger emergency underwater escape emergency breathing aid (“Air Pocket”) for use by those travelling offshore in the oil industry. At another level, I have spent my entire career trying to reduce the global burden of drowning through research that focuses on the physiological responses to immersion, especially in cold water. The numbers are imprecise, but around 3,000 people “drown” each day around the world. In the UK, although the number is thankfully falling, we still lose about one adult a day and one child a week due to drowning – drowning is the second most common cause of accidental death in most countries of the world but in comparison with other epidemics it is largely unrecognised. A large part of our work has examined the physiological and pathophysiological responses to immersion and the rescue, resuscitation and treatment of immersion casualties. It ranges from the cause of sudden death on immersion to prolonged survival underwater.

Do you think your work can make a difference?

I hope so. I know that many search and rescue (SAR) organisations and training establishments in the UK and abroad use our work in the training of their personnel and in their search and rescue policies and medical protocols. Our work is also used by leading industries, for example in the energy sector, to determine their policies for sending workers into different environments and determining the selection and protection of their work force. I am pretty confident that we have “impact”.

Therapeutic hypothermia has been shown to prevent brain damage. Can you tell us a bit more about it?

Hypothermia is something of a “twin edged sword”. On the one side hypothermia, on average, causes cardiac arrest at a deep body temperature of about 25 °C, although the range on this figure is very large with the lowest deep body temperature recorded with complete recovery being below 14°C. On the other side we have proposed as long ago as 1997 that selective brain cooling during submersion is the reason why some people, particularly children have survived up to 66 minutes of submersion in very cold water with full recovery. The hypoxic survival time of the brain is extended by hypothermia; with cerebral activity and therefore oxygen demand falling close to minimal levels at a brain temperature of 22°C. We think that in the right circumstances the initial cold shock response to immersion in cold water and the process of drowning, both of which are normally extremely hazardous, can result in a “drowned” individual with a brain protected from hypoxia by hypothermia. The same mechanism underpins some of the benefits of therapeutic hypothermia.

Prolonged survival underwater is a very rare occurrence, but when it happens, the individual is retrievable. From the applied perspective, this is important knowledge for the SAR community and we have produced a decision making guide for this group  that, for example, forms part of the Fire & Rescue Service National Operational Guidance Programme for in-water rescue.

You are currently “touring” your GL Brown Prize lecture around the UK and Ireland. In your presentation you’re talking about “life at the extremes” and our limits of physiological adaptations to environmental extremes. Would you say our body is more heat tolerant, due to our “equatorial ancestry”, or are both hot and cold environments presenting an equal challenge?

We are certainly a tropical animal; we are designed to live naked in an air temperature of 28 °C with a mean skin temperature of 33°C and deep body temperature controlled between 36.5 °C and 39 °C depending on what we are doing. The thing that makes us different is our intellect. If we were to rely on just our thermoregulatory system, we would be confined to our equatorial origins. Our intellect has allowed us to inhabit the rest of the planet via the use of clothing, building and heating. In so doing we have recreated our thermal tropical origins in the microclimate next to our skin, but in so doing we have reduced the stimuli to adapt in the ways other animals demonstrate.

Under normal, resting circumstances we have a deep body temperature (37 °C) that is about 7 °C below the upper lethal limit (hyperthermic death) and 12 °C  above the lower lethal limit (hypothermia death). Despite the bigger margin to death from hypothermia, we are better suited to lose heat than gain it: for each litre of blood at 37 °C that flows through the skin and returns to the deeper tissues at 36°C the body loses roughly 4.2 kJ of heat. As the maximum skin blood flow can be as much as 3-4 L.min-1, the same 1°C fall in the temperature of the blood off-loads up to 280W. In contrast to most other mammals that have none, humans have about 2.5 million sweat glands distributed over most of the body surface in densities ranging from 100 to 600 per square centimetre. If we evaporate all the sweat we can produce per hour (about 2L.hr-1) we can lose about 1200 W of heat. In contrast, in the cold piloerection (raising the hairs on our skin) traps little air because of our hairless state, maximum shivering only produces about 600W of heat. Finally, although body fat has similar thermal characteristics to cork, when maximally vasoconstricted we do not have much subcutaneous body insulation to counter cooling (although the trend seems to be for humans to have more insulation)!

What does a typical day involve?

Start work at home about 5am, usually reading, writing and emailing. Motorbike to work about 08:45, get in at 09:15. Meet colleagues and students to discuss some of the 20-30 projects (from experiments to writing projects) we have running at any given time. Maybe a meeting (see below), working lunch at the Café Parisien 150m from my office. Visit lab, discuss experiments, chat to PhD students, work on publications, administration (see below). Go to gym or do some exercise. Eat dinner, work until 21:00 then fall asleep in front of a film (my family evaluate films by how long it takes me to fall asleep watching them). Bed at 23:30.

Actually I do not have many “typical” days – I travel a lot giving talks, working with end-users of our work and doing field experiments and therefore spend quite a lot of time in hotels and away from the office.

What do you enjoy most in your job?

Discussing protocols and new data with students and colleagues. Meeting, talking with and helping those in the rescue services – great people.

What do you enjoy the least?

Administration and unnecessary, over-bearing and inhibiting bureaucracy. Meetings that go on for longer than a rugby match. The false distinction between “pure” and “applied” research; I agree with Sir Peter Medawar:  “the distinction between pure and applied science is false. There are only two types of science, good and bad”.

Tell us something about you that might surprise us…

I do the Nice Ironman every 5 years – it is cheaper than private health care. The next one is scheduled for 2019.

What advice would you give to students/early career researchers?

Be inquisitive and develop as wide a knowledge and interest base as you can. As we specialise and learn more and more about less and less, the person who can look across several areas with knowledge and understanding becomes a precious commodity. Be confident in your own abilities, including the ability to have good ideas. Be collegiate: talk and network to as many people as you can. If you haven’t already, learn to listen. Try not to prioritise “timeliness” over “quality”. Check out: https://www.linkedin.com/pulse/career-advice-i-wish-had-25-shane-rodgers.