BACKGROUND: Previous studies have shown that old age and cold temperatures are risk factors for bathing-related accidents (BRAs) in Japan. The differences between outdoor and indoor temperatures are believed to depend on the housing type (detached houses or apartment buildings). This study aimed to investigate the associations between age, temperature, and BRAs according to housing type in Japan. METHODS: We included cases in which patients were transported by ambulance from domestic bathrooms between April 2016 and March 2022 in Nagoya city. Age-specific BRA incidence rates measured by 5-year age groups, temperature-specific age-adjusted standardized incidence rates (SIRs) for BRA calculated by temperature quintile groups, and the BRA risk regarding temperature based on a time-stratified case-crossover (CCO) design were compared between detached houses and apartment buildings. RESULTS: We observed 4,848 ambulance dispatches owing to BRAs (3,083 in detached houses and 1,765 in apartment buildings; SIR for detached houses compared to apartment buildings: 1.37; 95% confidence interval [CI]: 1.33-1.43). The ratio of detached houses to apartment buildings in the age-specific BRA incidence was almost the same in middle-aged people, but it significantly increased from the age of 70 years onward (incidence rate ratio for the 70-74-years age group: 1.74; 95% CI: 1.43-2.11). Temperature-specific SIR for detached houses compared to apartment buildings was not significantly different in the hottest temperature quintile but increased significantly in the other colder temperature quintiles (SIR in coldest quintile: 1.56; 95% CI: 1.47-1.66). BRA risk based on CCO design increased significantly with a decrease in temperature in detached houses (risk ratio [RR] for 3 °C: 1.25; 95% CI: 1.05-1.47), but not in apartment buildings (RR for 3 °C: 1.07; 95% CI: 0.86-1.34). CONCLUSIONS Detached houses had higher BRA incidence rates than apartments. Older age and lower temperatures, which are risk factors for BRAs, were more prevalent in detached houses than in apartment buildings. Thus, public health measures that focus on detached houses are necessary for preventing BRAs in Japan.
Humans ; Japan/epidemiology* ; Aged ; Middle Aged ; Housing/statistics & numerical data* ; Baths/adverse effects* ; Ambulances/statistics & numerical data* ; Male ; Adult ; Female ; Temperature ; Incidence ; Aged, 80 and over ; Young Adult ; Age Factors ; Adolescent ; Child, Preschool ; Infant ; Child ; Risk Factors ; Infant, Newborn ; Accidents, Home/statistics & numerical data*

Heat stroke is a potentially fatal disorder that's caused by an extreme elevation in body temperature. We report here an unusual case of multiple organ failure that was caused by classical, nonexertional heat stroke due to taking a warm bath at home. A 68 year old diabetic man was hospitalized for loss of consciousness. He was presumed to have been in a warm bath for 3 hrs and his body temperature was 41 degrees C. Despite cooling and supportive care, he developed acute renal failure, disseminated intravascular coagulation (DIC) and fulminant liver failure. Continuous venovenous hemofiltration was started on day 3 because of the progressive oligouria and severe metabolic acidosis. On day 15, septic ascites was developed and Acinetobacter baumanii and Enterococcus faecium were isolated on the blood cultures. In spite of the best supportive care, the hepatic failure and DIC combined with septic peritonitis progressed; the patient succumbed on day 25.
Multiple Organ Failure/*etiology ; Male ; Liver Failure/*etiology ; Kidney Failure/*etiology ; Humans ; Heat Stroke/*complications/etiology ; Fatal Outcome ; Baths/*adverse effects ; Aged