Under normal conditions, your body can adapt to different ambient temperatures and maintain a constant body temperature. When this safety system fails, heat-related injuries occur. The most common are heat cramps, heat syncope, heat exhaustion and heat stress. These often occur during heat waves and affect very young, old, or debilitated people. A less well-studied threat is posed by exertional heat-related injuries (EHI). These occur in physically active people and may not be related to high temperatures. It has been studied in athletes, military personnel and in specific occupations. It has not been well-documented in people engaged in recreational sports such as football or those involved in ordinary activities such as gardening, washing the car and mowing the lawn. The current study looked at records people treated for EHI in U.S. hospital emergency departments.
* Researchers reviewed data from hospitals included in The National Electronic Injury Surveillance System from 1997-2006.
* Medical charts from the emergency departments were reviewed for a diagnosis of heat-related injuries.
* Cases were selected based on key words in patients’ records: heat, hot, dehydration, exhaustion, sun, temperature and weather.
* Other information collected included age, hospital admission or release record and the nature of the physical activity that led to symptoms.
* About 54,983 patients were treated between 1997 and 2006. Of these, 5,284 patients were admitted to the hospital. More male patients were hospitalized for EHIs (11.2 percent) than women (5.5 percent). There was a 133.5 percent increase during the 10-year study period.
* The mean age of the patients was 30.8 years and 71.9 percent were male. The largest group of patients (47.6 percent) consisted of people 19 years of age or younger.
* Sports or exercise were the most common causes of EHI. More than three-quarters of the patients reporting these activities while 11.0 percent were engaged in yard work when they became ill.
* Football accounted for most of the complaints (18.1 percent). Exercise was responsible for 15.9 percent and lawn mowing for 7.9 percent of the emergency cases treated at the hospital.
The estimates of EHI are based on data available from hospitals registered with National Electronic Injury Surveillance System. It does not include people suffering from EHI who were treated elsewhere. The study also does not document deaths related to EHI. The data on environmental conditions at the time of injury and other risk factors were not available. This makes it difficult to correlate the severity of the environmental conditions or the physical activity with symptoms.
Heat-related injury can occur even when a person is engaged in everyday activities such as playing sports or engaged in physical activity associated with working around the home, such as lawn mowing. Football appears to be the leading cause of EHI in people 19 years of age or younger. This phenomenon has been is known since 1970 and guidelines have been framed, but apparently only 50 percent of high school programs use them. Golf, another game played in the sun, seems to be responsible for EHI in the older population. This study highlights precautions that need to be incorporated during sports and yard activities, especially during summer. It also highlights the importance of health education in preventing EHI in the vulnerable population.
For More Information:
Exertional Heat-Related Injuries Treated in Emergency Departments in the U.S. between 1997-2006
Publication Journal: American Journal of Preventive Medicine, 2011
By Nicolas Nelson; Christy Collins, et al. The Center for Injury Research and Policy, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio