Indiana University’s newest environmental chamber capable of simulating extreme temperatures will help researchers better understand temperature tolerance.
The project, funded by the U.S. Department of Defense, aims to understand how people operate in extreme temperatures, particularly those in the Arctic. There are currently members of the military stationed in the Arctic, and IU Associate Professors Blair Johnson and Zac Schlader want to find out how people can safely maintain their presence in an extremely cold setting.
“You can only put on so many clothes before you become the Stay Puft Marshmallow Man or the kid on the Christmas Story movie where you can't move,” Johnson said. “So, we're trying to generate mechanisms that we can increase the body's internal heat production, and perhaps maybe you don't have to put on as many layers of clothes to stay warm.”
There has been an environmental chamber in the School of Public Health since the 1980s, which can create temperatures ranging from 4 degrees Celsius to 45 degrees Celsius. Johnson and Schlader say it is more limited in its ability to simulate extreme temperatures, and also smaller in size.
The new chamber, divided into two rooms, has a warm side and a cold side. The cold side can simulate temperatures ranging from -40 degrees Celsius to zero degrees Celsius. The warm side can create temperatures between zero degrees Celsius and 50 degrees Celsius, which is 122 degrees Fahrenheit. Johnson and Schlader said they can control the humidity, and that the setting in the warm side is of one in the shade. They say it is difficult to simulate heat from the sun.
With a grant of $915,000 to work with, it was cheaper for Johnson and Schlader to divide the chamber into two rooms instead of having one big room.
“When you go to a restaurant in town, you have to walk through the foyer and the vestibule to get to the inside of the restaurant,” Johnson said. “Well, that's there to buffer temperature changes, and so the warm side really acts to buffer that temperature change between the outside of the chamber and the cold side.”
Johnson and Schlader started their research in the chamber just last month. So far, they’ve begun studies on how the body regulates temperature and hydration. They have also simulated occupational heat exposure: they study the effects of a subject being in extreme heat for a long period of time.
“They dress like a worker and do a number of different tasks, walking on a treadmill or doing upper body work or something of that nature,” Schlader said.
The professors hope to better understand heat acclimation and find a way to accelerate the process and decrease the risk of heat illness. Extreme heat is the leading weather-related cause of death in the U.S., with an average of 1,300 deaths per year.
“Think general public: a heat wave hits, air conditioning fails. What can we do to keep them healthy?” Schlader said.
Johnson and Schlader take various safety precautions when using the chamber: they screen participants for underlying conditions that may impact their ability to take on extreme temperatures. They also constantly monitor the subject’s heart rate, blood pressure and skin temperature. And at least two people are with the subject in the chamber.
Johnson and Schlader said this tool will also give students hands-on learning experience and opportunity to do research early in their careers.
“Let's talk about, say, extreme cold, and then let's go experience it for just a short period of time,” Schlader said. “This is what this feels like, and turn a fan on, this is what wind chill feels like, as opposed to just sitting in a lecture talking about it.”
Johnson and Schlader also plan to do more research on cold resiliency.
“We want to give a drug that increases metabolic heat production on a chronic basis, to see if we can impact cold resiliency in a favorable way,” Johnson said.
