16 Volume 85 • Number 4 A D VANC EME N T O F T H E SCIENCE Introduction Throughout time, fishing has been and continues to be an important source of nutrition all over the world. In the U.S. and elsewhere, it is also an extremely popular recreational activity with many types, including ice fishing. A study from the U.S. Fish and Wildlife Service (2012) found that >1.9 million people participate in ice fishing activities annually. Additionally, those participants spent nearly 20 million days on the ice and $241 million on ice fishing equipment annually (U.S. Fish and Wildlife Service, 2012). Due to obvious climate variations, ice fishing within the U.S. is almost exclusive to the northern states. To participate in this activity, an ice fisher will trek onto a frozen lake surface and cut a hole in the ice to pass a baited fishing line into the water. The fisher typically will wait for a period of time for the baited hook to be taken by a fish swimming beneath the surface ice. This process can take several hours and poses the dangers of exposure and frostbite (Thiels et al., 2016). To help combat the cold and sometimes windy environment, the fisher will use a shelter (e.g., icehouse). These icehouses come in various styles and can range from temporary shelters akin to a pop-up tent to a more permanent hardened structure. Furthermore, some of these shelters have built-in or impromptu heating devices that can pose their own dangers. Propane heaters in particular, most of which are designed for outdoor use only, can create hazardous conditions resulting from elevated levels of carbon monoxide (CO) when used within an enclosed structure with inadequate ventilation (Take Me Fishing, 2022; Thiels et al., 2016; Yoon et al., 1998). Awareness of the potential dangers of CO poisoning is paramount in the ice fishing community. We conducted a search through various beginner ice fishing websites and found little to no discussion regarding the safe use of portable heaters or CO toxicity. Additionally, the recognition of symptoms of CO poisoning and the proper use of eective CO detectors are important aspects to consider in decreasing the life-threatening risk to this population (Hampson, 2016a; Thiels et al., 2016; Yoon et al., 1998). Based on firsthand experience with patients within the Hennepin Healthcare system, ice fishing is a common activity that leads to significant morbidity and mortality every winter from the prolonged use of propane heaters in icehouses. Yet published literature in this area is scarce (Thiels et al., 2016). Our study was designed to assess the baseline level of awareness and knowledge in a group of individuals who ice fish. This information can lead to further educational campaigns to promote the safe use of heaters and CO detectors. Communications with the Minnesota Department of Natural Resources and Minnesota Department of Health prior to conducting the study indicated a public need for the information. The study was reviewed by our institutional review board and determined to be exempt from oversight or written informed consent, as the study involved anonymous survey procedures only and, by completing the survey, individuals authorized the use of their responses for research purposes. Methods The population surveyed consisted of a voluntary sample of participants at the February Christopher T. Bird, MS, MD Department of Emergency Medicine, Hyperbaric Medicine, The University of Kansas Health System, University of Kansas Bjorn C. Westgard, MA, MD Department of Emergency Medicine, Hyperbaric Medicine, Hennepin Healthcare Department of Emergency Medicine, University of Minnesota Risks and Understanding of Carbon Monoxide Poisoning in an Ice Fishing Community Abs t r ac t Ice fishing is an activity that can lead to accidental carbon monoxide (CO) poisoning from the prolonged use of propane heaters in icehouses. Published literature on this topic is scant. We conducted a survey of adults registered for a Minnesota ice fishing festival to assess risks for CO poisoning. Participants were surveyed about their knowledge of CO poisoning and the details of their ice fishing and icehouses. Of 387 participants, 101 adults completed our survey. Mean age was 44 years, and 73% identified as male. Among respondents, 85% fish in icehouses and 79% indicate they consume alcohol while fishing. Furthermore, 98% of respondents use propane heaters for an average of 9.66 hr; however, only 33% have CO detectors. While 92% of respondents are aware of CO poisoning and 84% know some of the symptoms, only 34% would seek medical attention for symptoms of CO poisoning. CO poisoning is a risk among ice fishers. Furthermore, while a majority of respondents are aware of CO poisoning, few have CO detectors or would seek medical attention for symptoms of CO poisoning. Our survey provides baseline data that can be used for public health outreach about the risks of CO among ice fishers.