This study investigates the relationship between temporal changes in temperatures characterizing local urban heat islands (UHIs) and heat-related illnesses (HRIs) in seven major cities of California. UHIs, which are a phenomenon that arises in the presence of impervious surfaces or the lack of green spaces exacerbate the effects of extreme heat events, can be measured longitudinally using satellite products. The two objectives of this study were: (1) to identify temperature trends in local temperatures to characterize UHIs across zip code tabulation areas (ZCTAs) in the seven observed cities over a 22-year period and (2) to use propensity score and inverse probability weighting to achieve exchangeability between different types of ZCTAs and assess the difference in hospital admissions recorded as HRIs attributable to temporal changes in UHIs. We use monthly land surface temperature data derived from MODIS Terra imagery from the summer months (June-September) from 2000 to 2022. We categorized ZCTAs (into three groups) based on their monthly land surface temperature trends. Of the 216 ZCTAs included in this study, the summertime land surface temperature trends of 43 decreased, while 161 remained unchanged, and 12 increased. Los Angeles had the greatest number of decreased ZCTAs, San Diego and San Jose had the highest number of increased ZCTAs. To analyze the number of monthly HRI attributable to changes in UHI, we used inverse probability of treatment weighting to analyze the difference in HRI between the years of 2006 and 2017 which were two major extreme heat events over the entire State. We observed an average reduction of 3.2 (95 % CI: 0.5; 5.9) HRIs per month and per ZCTAs in decreased neighborhoods as compared to unchanged. This study emphasizes the importance of urban climate adaptation strategies to mitigate the intensity and prevalence of UHIs to reduce health risks related to heat.

Heat-related illness (HRI) is commonly considered an acute condition, and its potential long-term consequences are not well understood. We conducted a population-based cohort study and an animal experiment to evaluate whether HRI is associated with dementia later in life.
The Taiwan National Health Insurance Research Database was used in the epidemiological study. We identified newly diagnosed HRI patients between 2001 and 2015, but excluded those with any pre-existing dementia, as the study cohort. Through matching by age, sex, and the index date with the study cohort, we selected individuals without HRI and without any pre-existing dementia as a comparison cohort at a 1:4 ratio. We followed each cohort member until the end of 2018 and compared the risk between the two cohorts using Cox proportional hazards regression models. In the animal experiment, we used a rat model to assess cognitive functions and the histopathological changes in the hippocampus after a heat stroke event.
In the epidemiological study, the study cohort consisted of 70,721 HRI patients and the comparison cohort consisted of 282,884 individuals without HRI. After adjusting for potential confounders, the HRI patients had a higher risk of dementia (adjusted hazard ratio [AHR] = 1.24; 95% confidence interval [CI]: 1.19-1.29). Patients with heat stroke had a higher risk of dementia compared with individuals without HRI (AHR = 1.26; 95% CI: 1.18-1.34). In the animal experiment, we found cognitive dysfunction evidenced by animal behavioral tests and observed remarkable neuronal damage, degeneration, apoptosis, and amyloid plaque deposition in the hippocampus after a heat stroke event.
Our epidemiological study indicated that HRI elevated the risk of dementia. This finding was substantiated by the histopathological features observed in the hippocampus, along with the cognitive impairments detected, in the experimental heat stroke rat model.

Heat Related Illness (HRI) in dogs is expected to increase as heatwaves surge due to global warming. The most severe form of HRI, heat stroke, is potentially fatal in dogs. The current study investigated the incidence and risk factors for HRI in dogs in NSW, Australia, from 1997 to 2017. We identified 119 HRI cases during this period, with a fatality rate of 23%. Dog breeds at elevated risk of HRI were Australian Stumpy Tail Cattle Dog, British Bulldog, French Bulldog, Maremma Sheepdog, Italian Greyhound, Chow Chow, Airedale Terrier, Pug, Samoyed, English Springer Spaniel, Labrador Retriever, Golden Retriever, Cavalier King Charles Spaniel, Border Collie, Staffordshire Bull Terrier, and pooled non-Australian National Kennel Council breeds (which included the American and Australian Bulldog) when compared with cross breeds (i.e., the reference variable). As expected, HRI cases were more likely in December and January, during the Australian summer and during hotter years (e.g., 2016). There were no differences in the risk of HRI between males and females nor between desexed or un-desexed dogs; but older dogs were at increased risk of HRI. These findings underscore the need for data collection that will enable the incidence of HRI in dogs to be monitored and to better understand canine risk factors particularly as temperatures will continue to rise due to global warming. The risk of mortality from HRI underpins the need for education programs focussed on prevention and early identification of HRI so that owners present affected dogs to their veterinarian as promptly as possible.

Climate change is known to increase the frequency and intensity of hot days (daily maximum temperature ≥30°C), both globally and locally. Exposure to extreme heat is associated with numerous adverse human health outcomes. This study estimated the burden of heat-related illness (HRI) attributable to anthropogenic climate change in North Carolina physiographic divisions (Coastal and Piedmont) during the summer months from 2011 to 2016. Additionally, assuming intermediate and high greenhouse gas emission scenarios, future HRI morbidity burden attributable to climate change was estimated. The association between daily maximum temperature and the rate of HRI was evaluated using the Generalized Additive Model. The rate of HRI assuming natural simulations (i.e., absence of greenhouse gas emissions) and future greenhouse gas emission scenarios were predicted to estimate the HRI attributable to climate change. Over 4 years (2011, 2012, 2014, and 2015), we observed a significant decrease in the rate of HRI assuming natural simulations compared to the observed. About 3 out of 20 HRI visits are attributable to anthropogenic climate change in Coastal (13.40% [IQR: -34.90,95.52]) and Piedmont (16.39% [IQR: -35.18,148.26]) regions. During the future periods, the median rate of HRI was significantly higher (78.65%: Coastal and 65.85%: Piedmont), assuming a higher emission scenario than the intermediate emission scenario. We observed significant associations between anthropogenic climate change and adverse human health outcomes. Our findings indicate the need for evidence-based public health interventions to protect human health from climate-related exposures, like extreme heat, while minimizing greenhouse gas emissions.

BACKGROUND: A large body of scientific evidence has established the impact of increased temperatures on human health. There is a relationship between extreme heat (either incremental temperature increase or heatwaves), and heat-related illnesses. This study aimed to collate the research findings on the effects of extreme heat on heat-related illness in a systematic review and meta-analysis, and to provide robust evidence for needed public health intervention.
METHODS: We conducted a search of peer-reviewed articles in three electronic databases (PubMed, EMBASE, and SCOPUS), from database inception until January 2022. A random-effects meta-analysis model was used to calculate the pooled relative risks (RRs) of the association between high temperature and heat-related illness outcomes. A narrative synthesis was also performed for studies analysing heatwave effects. Assessment of evidence was performed in three parts: individual study risk of bias; quality of evidence across studies; and overall strength of evidence.
RESULTS: A total of 62 studies meeting the eligibility criteria were included in the review, of which 30 were qualified to be included in the meta-analysis. The pooled results showed that for every 1 °C increase in temperature, when measured from study-specific baseline temperatures, direct heat illness morbidity and mortality increased by 18 % (RR 1.18, 95%CI: 1.16-1.19) and 35 % (RR 1.35, 95%CI: 1.29-1.41), respectively. For morbidity, the greatest increase was for direct heat illness (RR 1.45, 95%CI: 1.38-1.53), compared to dehydration (RR 1.02, 95%CI: 1.02-1.03). There was higher risk for people aged >65 years (RR 1.25; 95 % CI: 1.20-1.30), and those living in subtropical climates (RR 1.25; 95 % CI: 1.21-1.29).
CONCLUSIONS: Increased temperature leads to higher burden of disease from heat-related illness. Preventative efforts should be made to reduce heat-related illness during hot weather, targeting on the most vulnerable populations. This is especially important in the context of climate change.

Objective: Thermoregulatory dysfunction after spinal cord injury (SCI) impairs quality of life and predisposes persons to life-threatening sequela of heat-related illness (HRI) in conditions of high ambient temperature. SCI clinicians currently have no objective way to predict which persons are at greatest risk of HRI. Evaporative cooling via sweating is the body\'s most efficient mechanism of heat dissipation. The relationship between the neurological level of injury (NLOI) and the degree of sudomotor dysfunction is not well defined. This study examines the relationship between the NLOI and sweating level of injury (SwLOI). This information can assist SCI clinicians in identifying individuals with SCI who have most impaired sudomotor function and thus highest risk of HRI.Design: Observational.Setting: Human physiology laboratory.Participants: 10 persons with tetraplegia (TP), 14 with paraplegia (PP) and 10 able-bodied (AB).Intervention: Passive heat stress (1°C rise in core temperature) with sweat responses (SR) quantified with the starch iodine test.Outcome measures: The most caudal dermatomal level in which sweating was visualized was recorded as the SwLOI, which was compared to the NLOI. Minimum, maximum and median differences between NLOI and SwLOI were calculated.Results: Persons with tetraplegia demonstrated no SR. Persons with paraplegia demonstrated SR at a median of 1 level below NLOI. Able-bodied controls demonstrated sweating on all skin surface areas.Conclusions: Persons with motor complete tetraplegia lack evaporative cooling capacity through SR during passive heat stress predisposing them to HRI. Meanwhile, persons with paraplegia sweat on average 1 dermatomal level below their NLOI.

This study aims to compare the Bouchama heatstroke (B-HS) and Japanese Association for Acute Medicine heatstroke (JAAM-HS) criteria with regard to the diagnosis and prediction of mortality and neurological status of heatstroke patients.
This multicenter observational study recruited eligible patients from the emergency departments of 110 major hospitals in Japan from 1 July to 30 September, 2014.
A total of 317 patients (median age, 65 years; interquartile range, 39-80 years) were included and divided into the B-HS, JAAM-HS, and non-HS groups, with each group consisting of 97, 302, and 15 patients, respectively. The JAAM-HS (1.0; 95% confidence interval [CI], 0.87-1.0) and B-HS (0.29; 95% CI, 0.14-0.49) criteria showed high and low sensitivity to mortality, respectively. Similarly, the JAAM-HS (1.0; 95% CI, 0.93-1.0) and B-HS (0.35; 95% CI, 0.23-0.49) criteria showed high and low sensitivity to poor neurological status, respectively. Meanwhile, the sequential organ failure assessment (SOFA) scores demonstrated good accuracy in predicting mortality among heat-related illness (HRI) patients. However, both JAAM-HS and B-HS criteria could not predict in-hospital mortality. The AUC of the SOFA score for mortality was 0.83 (day 3) among the HRI patients. The patients\' neurological status was difficult to predict using the JAAM-HS and B-HS criteria. Concurrently, the total bilirubin level could relatively predict the central nervous system function at discharge.
The JAAM-HS criteria showed high sensitivity to mortality and could include all HRI patients who died. The JAAM-HS criterion was considered a useful tool for judgement of admission at ED. Further investigations are necessary to determine the accuracy of both B-HS and JAAM-HS criteria in predicting mortality and neurological status at discharge.

Heat poses a significant occupational hazard for labour-intensive workers in hot and humid environments. Therefore, this study measured the prevalence of heat-stress symptoms and impact of heat exposure on labour-intensive industries within the Monsoonal North region of Australia. A cohort of 179 workers completed a questionnaire evaluating environmental exposure, chronic (recurring) and/or severe (synonymous with heat stroke) symptoms of heat stress, and impact within work and home settings. Workers reported both chronic (79%) and severe (47%) heat stress symptoms, with increased likelihood of chronic symptoms when exposed to heat sources (OR 1.5-1.8, p = 0.002-0.023) and decreased likelihood of both chronic and severe symptoms when exposed to air-conditioning (Chronic: OR 0.5, p = <0.001, Severe: OR 0.7, p = 0.019). Negative impacts of heat exposure were reported for both work and home environments (30-60% respectively), highlighting the need for mitigation strategies to reduce occupational heat stress in the Monsoonal North.

In 2020, Japan will host the Tokyo Olympic and Paralympic Games in 2020 (Tokyo 2020) which will involve a large population influx from various countries to Tokyo, the most populated city in Japan. We summarize the potential health risks for visitors to Tokyo 2020, related to communicable disease risks and other health threats, based on recent national and local surveillance reports.
We reviewed up-to-date surveillance reports published by the National Institute of Infectious Diseases and Tokyo Metropolitan Infectious Disease Surveillance Center.
Communicable disease risks for vaccine-preventable illnesses such as measles and rubella, as well as food and waterborne diseases represent the most likely risks. The risk of acquiring vector-borne diseases is considered low in Japan. On the other hand, however, heat-related illness represents a potential risk, as Tokyo 2020 is scheduled during the hottest season in Japan, with temperatures generally expected to exceed 30 °C.
Maintaining an up-to-date routine vaccination schedule is highly recommended for visitors attending the Tokyo 2020 and appropriate hygiene measures for food and waterborne diseases as well as health promotion for heat-related illness. It may also be useful to increase the number of multilingual triage clinicians whom can be placed within emergency departments during the Tokyo 2020 to provide first contact services and coordination of emergency care among non-Japanese speaking visitors to Tokyo.

As the number of youth sports participants continues to rise over the past decade, so too have sports related injuries and emergency department visits. With low levels of oversight and regulation observed in youth sports, the responsibility for safety education of coaches, parents, law makers, organizations and institutions falls largely on the sports medicine practitioner. The highly publicized catastrophic events of concussion, sudden cardiac death, and heat related illness have moved these topics to the forefront of sports medicine discussions. Updated guidelines for concussion in youth athletes call for a more conservative approach to management in both the acute and return to sport phases. Athletes younger than eighteen suspected of having a concussion are no longer allowed to return to play on the same day. Reducing the risk of sudden cardiac death in the young athlete is a multi-factorial process encompassing pre-participation screenings, proper use of safety equipment, proper rules and regulations, and immediate access to Automated External Defibrillators (AED) as corner stones. Susceptibility to heat related illness for youth athletes is no longer viewed as rooted in physiologic variations from adults, but instead, as the result of various situations and conditions in which participation takes place. Hydration before, during and after strenuous exercise in a high heat stress environment is of significant importance. Knowledge of identification, management and risk reduction in emergency medical conditions of the young athlete positions the sports physical therapist as an effective provider, advocate and resource for safety in youth sports participation. This manuscript provides the basis for management of 3 major youth emergency sports medicine conditions.