The data I collected by performing the experiment, how I analyzed it, and the conclusions I drew from it
Go Home| Environment | Environment Temp. | Body temp. before activity | Body temp. after activity | Body temp. after cooldown | Length of Cooldown | Change after exercise |
| Room temp. | 72° | 98.3° | Not Measured | Not Measured | Not Measured | Not Calculated |
| Warm | 75.4° | 98.4° | 98.5° | 98.8° | 10 min. | 0.4° |
| Cold | 70° | 98.6° | 98.4° | 98.7° | 10 min. | 0.1° |
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| Difference (warm - cold) | Difference | Difference | ||||
| -0.2° | 0.1° | 0.1° | ||||
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| Difference (warm - room) | ||||||
| 0.1° | ||||||
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| Difference (room - cold) | ||||||
| -0.3° | ||||||
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These results are about what I expected. In general, the differences are small enough that I consider them to be within the margin of error. Allowing for a bit of variance in the thermometer's measurements (I have never tested its accuracy), it shows that the body is indeed maintaining the temperature setpoint even while the two factors of environmental temperature and increased muscle activity are simultaneously working against it.
I measured out the lengths of exercise and cooldown with a timer, so they are consistent between the warm and cold environments.
An important note is that I did get somewhat sweaty after exercising outdoors. This is an example of the feedback loop at work. The thermoreceptors detected the increased temperature and signaled it to the hypothalamus (brain), which commanded sweating by expanding blood vessels to move blood closer to the skin and opening pores to allow heat to dissipate. (Explore the feedback loop in more detail)
The purpose of this experiment was to determine how the body maintains homeostasis by regulating its internal temperature and how it responds to changes in temperature. My hypothesis states that, if the body's internal temperature is changed from its setpoint, then the negative feedback loop in the body designed to regulate temperature will return it to its setpoint by either sweating or shivering, because the change will be detected by thermoreceptors and signaled to the hypothalamus, which will trigger the appropriate response, either sweating for high temperatures or shivering for low temperatures. To test the validity of this hypothesis, I took a baseline measurement of my body temperature at rest in a room temperature environment, then I measured my temperature at rest and after exercise in a warm environment and a cold environment to test the effects of changes in ambient temperature and the internal production of heat during muscle activity. Here I must admit that I have never tested the accuracy of our thermometer, but I do know that the temperature reading can vary slightly depending on how firmly I seat it in my ear, so I will allow for about ±0.2° of variance. If I had the time, I could theoretically profile our thermometer and account for this more accurately, but at this point I must regard it as a level of potential error. Even taking this into consideration, the results are what I expected, with little variance in my body temperature between every scenario. This supports my hypothesis, demonstrating that the human body can regulate its temperature to maintain its setpoint even when multiple forces are working against it.
As always, I could theoretically commit more resources (time, research, potentially money) and collect more accurate data, but that would exceed the scope of this assignment. I have already spent more time on this than I was supposed to. I'm designing an experiment, not just performing it forever!
There were some unforeseen variables in this experiment. It got colder outside faster than I expected, so I was still waiting for the peak temperature until it started declining and I realized I had missed it. It was also warmer in the basement than I expected. Thankfully, there was still a noticeable temperature difference between the two environments, though not as much as I had hoped. Additionally, I had not fully considered the potential effects of any variance in our thermometer's measurements, especially since that variance is unknown. I would have to test it myself, as even if I looked up what it is rated for, it is getting older and perhaps losing some accuracy. Ideally I would take my temperature three times and take the average, but the covers for it are not free and I did not want to use an entire pack for a school project.
It would be interesting to look into how illness affects the body's ability to (or methods of) regulate its temperature to maintain homeostasis. If they wanted to do a lab similar to this, one could take some baseline temperature measurements on a normal day, then they could take those same measurements while they were sick and compare them. It might give some interesting results. They could keep it simple and take the same measurements that this experiment took, or they could devise a more elaborate plan to collect better data. Again, I did not do anything elaborate because that would have exceeded the scope of this project. Otherwise, they could just research it as an additional component of the feedback loop.