Ice fishing injuries: Beyond hooks and hypothermia

As an introduction to a classic Upper Midwest winter ritual, Minnesota native Johnathon M. Aho, M.D., Ph.D., of Mayo Clinic in Rochester, Minnesota, invited fellow Mayo Clinic surgery resident and Atlanta native Cornelius A. Thiels, D.O., of Mayo Clinic's Minnesota campus, to join him on an ice fishing trip. While on this trip, the two conceived a unique study concept, a review of ice fishing injuries compared to traditional fishing injuries.

"As general surgery residents who spend time working on the trauma service, Dr. Aho and I had seen unfortunate outcomes from ice fishing," says Dr. Thiels. "While practicing this sport ourselves, we noted there were some unique risks, which at first may not be obvious to those who have not been ice fishing before."

The two residents felt the National Electronic Injury Surveillance Systems (NEISS) database would allow them to study this issue at no cost, and would allow them to generate data to drive education for providers and the public about ice fishing.

The study and its findings

The study, published in the July 2016 issue of The American Journal of Emergency Medicine, looked at initial emergency department visits from the NEISS-All Injury Program from 2009 to 2014, analyzing all cases of fishing-related injury. Admission and transfer rates served as primary endpoints, and secondary endpoints were anatomical injury categories.

Descriptive analyses between patients injured through ice or traditional fishing methods revealed that 85 (1 percent) of the 8,220 cases were related to ice fishing. These injuries occurred by far most commonly in males (88 percent) and in those with a mean age under 40 (39.4 ± 17.5 years old).

The most common ice fishing-related injuries identified included:

  • Orthopedic or musculoskeletal, likely related to slips on the ice (46 percent)
  • Minor trauma, such as lacerations, abrasions, contusions, punctures and hook injuries (37 percent)
  • Major trauma, such as amputation, organ space injury and closed-head injuries, including concussions (6 percent)
  • Hot thermal injuries, likely due to heating systems used in ice houses (5 percent)
  • Immersion/drowning (5 percent each)
  • Cold thermal injuries (1 percent)

Discussion of findings and applications for trauma care

Dr. Thiels advocates for trauma providers to be well aware of injuries associated with sports common in their regions, such as diving in Florida and ice fishing in Minnesota. While he believes Upper Midwest trauma providers are aware ice fishing has dangers, he also thinks it is important to be aware of some specifics found in this study, such as injuries sustained, population affected, and injury rates and severity.

Dr. Thiels points to several aspects of the findings as important for trauma practitioners:

Injuries sustained from ice fishing

Ice fishing is increasing in popularity and with it ice fishing injuries. While most ice fishing injuries are orthopedic or musculoskeletal and easy to treat, practitioners should be prepared to treat anything, ranging from drowning to inhalation injuries. Ice fishing carries unique risks, especially thermal injuries or potential carbon monoxide poisoning from space heaters that are commonly used inside ice houses to keep warm.

Perhaps counterintuitively, cold thermal injuries ranked low on the list of the most common traumas sustained while ice fishing. Hypothermia did not affect any of the patients studied.

"We expected to see more cold thermal injuries such as frostbite," says Dr. Thiels. "This may be due to a reporting bias or sampling issues, but ice fishers are often highly experienced and prepared outdoors people. Typical gear includes ice houses and heaters to stay warm, and this may explain the low rate of cold thermal injuries. Also, I think burn injuries and inhalation injuries are often not on people's radars as potential hazards if they have not gone ice fishing before."

Population represented in injury data

Individuals injured most often from ice fishing are largely young and male. This population likely reflects more of the sport's demographic than those at risk of injury in ice fishing, according to Dr. Thiels, noting that young males are at higher risk of trauma-related injury generally, frequently connected to alcohol consumption.

Rates and severity of injuries

Injuries, while rare, do occur, and they may be more severe than those incurred in traditional fishing. Injury numbers for ice fishers were lower than those in traditional fishing due to the fact that ice fishing is much less common and only occurs in more northern states where lakes freeze, while NEISS captures data evenly for the entire U.S. This database also did not support incidence research, as the number of ice fishing trips completed in the study time period is unknown.

The researchers did find greater injury severity with ice fishing compared with traditional fishing, which they theorize may be due to reporting bias or reflect the more severe ice fishing environment. In addition, ice fishing often involves power tools for drilling in the ice and propane space heaters for heating the ice house, both of which can cause serious injuries.

Rates of transfer and admission

Transfer, as well as admission, is higher with ice fishing injuries, due to the greater severity of ice fishing injuries compared with traditional fishing injuries. Additionally, ice fishing is typically done in rural settings outside of major metropolitan areas, making Level III and IV trauma centers more likely to see these patients, leading to a greater transfer rate to higher levels of care.

Alcohol involvement

While the NEISS database does not reliably capture intoxication rates, the investigators feel strongly from their research that it plays a role in ice fishing injuries.

"Ice fishing is a sport that commonly involves alcohol, and this can be a deadly combination," says Dr. Thiels. "Alcohol results in poor judgment and thus does not mix well with being out on the ice, exposed to cold temperatures, working with sharp objects such as knives and hooks, and using equipment such as augers and space heaters."

Public education messages from this study

The researchers believe that several public education messages derive from this study and encourage trauma practitioners to communicate the following ice fishing safety tips in their communities:

  • Only go out ice fishing when conditions are safe, checking with local agencies for ice conditions and weather.
  • Take time to plan before going ice fishing.
  • Bring appropriate gear and wear warm clothing that covers all of your skin.
  • Consume alcohol safely — not excessively — while ice fishing, as this sport requires good judgment to continually assess ice thickness and weather conditions.
  • Use the buddy system: Do not go ice fishing alone, and go with an experienced ice fisher.
  • Always tell a friend or family member where you are going.
  • Use only ventilated ice fishing houses and quality heating devices.

"Ice fishing, when conducted in a safe and responsible manner, can be a safe sport, and we are not trying to discourage it," says Dr. Thiels. "However, we do want to help educate the public so that it is aware of the risks and can take steps to mitigate the risks."

For more information

National Electronic Injury Surveillance System (NEISS). United States Consumer Product Safety Commission.

Mayo Clinic. Saving Lives With Gus: Ice Fishing Safety.

Thiels CA, et al. Injury patterns and outcomes of ice fishing in the United States. The American Journal of Emergency Medicine. 2016;34:1258.