A few weeks ago, I wrote a post about mouth temperature and how it can impact the reliability of a breath test. I wanted to show the impact that even a small change in mouth temperature, from a few seconds of swishing hot water to a few seconds of sucking an ice cube, could have on an blood alcohol reading.
You can see how the results of my blood alcohol test go up and down based on what I put in my mouth in this video. These factors would only have impacted the temperature of my mouth by a few degrees, and the effect was not prolonged. In real-world circumstances, a prolonged impact from increased or decreased mouth temperature may have a more significant impact on the results of the test.
In any event, the proof is in the science. And you can see it here.