February, 2003, Biology Experiment:

Skin Temp Response Time

- Purpose
- Background Information
- Equipment & Supplies
- Software & Probeware Set-up
- Experimental Procedure
- Data Analysis
- Conclusions and Extensions

PASPORT Skin/Surface Temperature Probe
(PS-2131)

PASPORT Skin/Surface Temperature Probe

 Cold Pack

Purpose:

Students will use a Skin/Surface Temperature Probe to measure the change in skin temperature before and after applying both a cold pack and heat pack to a student's arm.
 

Background Information:

We have two basic physiologic mechanisms to maintain our body's core temperature during exposure to cold:

  1. reducing skin temperature, which then reduces the difference between the skin temperature and the environment and slows heat loss, and

  2. increasing heat production through the act of shivering. When the body is exposed to cold, blood is diverted away from our skin and the extremities to the trunk by a process called vasoconstriction. This causes a decrease in the size of blood vessels in the skin and a reduction of blood flow. If exposure to the cold continues, the deep cooling reaches the nerve endings, then the small blood vessels. Eventually, even the muscles may be cooled.
Skin Temp Diagram
Enlarge Diagram
Source: Molson Medical Informatics, McGill University

The body's natural reaction to heat is sweating, which serves two main purposes. First, it cools the body. Secondly, it's one of the primary methods for clearing contaminants from our system. When our body heats up, the heart rate increases to pump the warmed blood away from the internal organs toward the skin. Our blood vessels dilate, which increases the volume of blood and flow to the skin. Heat is then transferred from the blood to the sweat and then released into the air from the skin's surface. The end result is the cooled blood reduces our body temperature.

This experiment can be done with commercially available hot/cold packs that are used for first-aid purposes.

Hypothesize: Will a student's skin temperature return to its normal level quicker after having a cold source or heat source applied? Why?

Back to top

Equipment & Supplies:

For each lab group:

Back to top

Software & Probeware Set-up:

  1. Ensure that your USB Link or Xplorer is connected to the computer.

  2. Click on one of the links below to download a pre-configured DataStudio file for this experiment and then open the file.

    PASPORT users:  Windows (.zip file) or Macintosh (.sit file)

    When the file is opened, you should see a Graph Display of Temperature vs. Time, as well as a Digits Display of Temperature.

  3. Connect the Skin/Surface Temperature to the Xplorer or USB Link.

  4. Resize and arrange the display as needed.

Back to top

Experimental Procedure:

Equipment Setup:
  1. The probe is designed to be either held on the skin surface or secured to the skin using adhesive medical tape. The sensing element is insulated from contact on one side, so you measure the surface you are interested in, rather than the surface and the finger holding the probe in place.

Data Collection & Recording:

  1. Click the Start button ( ) to begin collecting temperature data.

  2. Place the probe on a student’s forearm and hold in place, or use the adhesive medical tape.

  3. Allow the temperature reading to stabilize for approximately 15 seconds.

  4. Click the Stop button ( ) to end data collection.

  5. Remove the probe and apply the cold pack to the student’s forearm. Wait approximately 1 minute and remove the cold pack.

  6. Place the probe on the student’s forearm where the cold pack had been. Hold in place or use the adhesive medical tape.

  7. Click the Start button ( ) to begin collecting temperature data.

  8. Monitor the DataStudio graph and look for the temperature reading to return to the initial level prior to using the cold pack.

  9. Click the Stop button ( ) to end data collection.

  10. Now repeat steps 5 – 9, this time using the hot pack.

Back to top

Data Analysis:

  1. Scale the axes to fit the data using the Scale to Fit button ( ) in the Graph toolbar.

  2. Examine the graph and study the data. Which data run had the quickest response rate?

Back to top

Conclusions and Extensions:

  1. How did the temperature response rate differ between the two runs?

  2. Explain why a difference occurred.

  3. Compare the data collected to the student’s subjective report of what each trial felt like.

  4. Try different locations on the student’s arm (i.e. upper vs. lower, top vs. underside)


Back to top