Summer’s almost over, but you should save this idea for next time you’re feeling too hot. It turns out that the best way to cool yourself down is by eating small pieces of ice—like those found in your favorite slushy.
You can see a short video about this study on the Weather Channel, and you can read a bit more about it here, at the Washington Post.
The Weather Channel’s video says:
Here’s what multiple studies found: Drinking a slushy can drop your internal body temperature by 1 degree in 20 minutes
and
The slushy method has been tested and works for firefighters, cyclists, and triathletes.
The video explains that when you ingest tiny pieces of ice, your body sends energy to your belly to melt them. This draws energy (and heat) away from the rest of your body, cooling you off.
a) Before reading on, how might you conduct an experimental study to test the slushy method of cooling? What would your IV need to be? What would your DV be?
Now read these lines from the Washington Post journalist to see how close these studies came to your answer in a).
[A] study on Australian firefighters found that drinking a big slushy was just as effective at lowering core body temperature as sitting in a tub of cool water up to your bellybutton.
b) According to this summary, there were at least two groups in this Australian firefighters study. The journalist does not mention a control group, but do you think they would need one? Why or why not?
The Post article included a subsection asking, How big does the slushy need to be?
The amount of slushy you need to cool down depends on your weight.
Both Maley’s 2020 study and the earlier 2014 study used a similar formula that translates to about one fluid ounce per eight pounds of body mass. For the firefighters in the 2014 study, who weighed around 185 pounds, that would be 23 ounces, which is roughly one large Slurpee from 7-Eleven.
c) Even though Maley’s two studies followed a 1 fluid ounce per 8 pounds rule, that doesn’t necessarily mean the 1-to-8 ratio is ideal. How could you design a study that would test the relative efficacy of different ratios of slushy-to-body weight? Specifically, what would the IV need to be to test this question? What levels might you test? What would the DV be?
The Post article also asked about timing:
It doesn’t matter how fast you drink it, as long as you don’t let it melt. The firefighters in the 2014 study slurped their slushies in 15 minutes after exercising, while in the 2020 study, they sipped them over the course of half an hour before exercising. The results were the same: Their internal body temperatures dropped by about 1 degree Fahrenheit.
d) Some researchers would prefer to test the timing question in a single experiment. How could you design a study that would test the relative efficacy of different timings of slushy consumption on body temperature? What would your IV and its levels be? What would the DV be?