Yup! Nicht Gut.
The good part about dry ice is that it's really cold. I used to pick up some free dry ice at the grocery store when the delivery truck came Thursday evening. I'd throw it in the ice box the day before we left for a trip and the day of departure throw in a block or two of regular ice - the ice would last lomger that way. One day before a big trip I had several plastic buckets of dry ice and really stuffed the box.Now the down side. Dry ice contains carbon dioxide. Any thing that is in your icebox will get carbonated - like milk and watermelon, for example. The really down side is that carbon dioxide is heavier than air and settles to the bottom of the box, and, if the drain hole is open, flows into the bildge. The first night out on thae big trip (see above) I woke up in the night with breathing difficulty. I almost couldn't get out of the aft cabin berth. My wife was not wide awake and didn't feel well either. At the time I didn't know what the problem was but my first reaction was to go outside and get some fresh air. Once I could think straight again I figured it was the ice. After opening up all the hatches and getting some ventillation the problem went away. Fortunately our daughter in the V-berth was higher than we were and was't affected much. Certainly quantity is a factor. I've never used dry ice since and we now have refrigeration.