Heat-health messaging in Canada: A review and content analysis of public health authority webpages and resources.

Background: With the growing threat posed by extreme heat, heat-health messaging communicated by public health authorities is critical for raising community awareness and action. This study sought to (i) identify what heat-health content is shared online by Canadian public health authorities and (ii) analyse the material to develop an understanding of the content included within the resources.

Study Design: Qualitative content analysis.

Effects of 24-h sleep deprivation on whole-body heat exchange in young men during exercise in the heat.

Sleep deprivation has been associated with impaired thermoregulatory function. However, whether these impairments translate to changes in whole-body heat exchange during exercise-heat stress remains unknown. Therefore, following either a night of normal sleep or 24 h of sleep deprivation, 10 young men (mean (SD): 23 (3) years) completed three 30-min bouts of semi-recumbent cycling at increasing fixed rates of metabolic heat production (150, 200, 250 W/m), each separated by a 15-min rest in dry heat (40 °C, ~ 13% relative humidity).

An exploratory survey assessing the determinants of heat stress and heat strain in the Canadian mining industry from the worker's perspective.

With mines extending deeper and rising surface temperatures, workers are exposed to hotter environments. This study aimed to characterize heat stress and strain in the Canadian mining industry and evaluate the utility of the Heat Strain Score Index (HSSI), combined with additional self-reported adverse health outcomes. An exploratory web-based survey was conducted among workers ( = 119) in the Canadian mining industry.

Effects of daylong exposure to indoor overheating on enterocyte damage and inflammatory responses in older adults: A randomized crossover trial.

We evaluated enterocyte damage (IFABP), microbial translocation (sCD14), and inflammatory responses (TNF-α, IL-6, CRP) in 16 older adults (66-78 years) during 8 hours rest in conditions simulating homes maintained at 22°C (control), the 26°C indoor temperature upper limit proposed by health agencies, and homes without air-conditioning during heatwaves (31°C, 36°C). Relative to 22°C, IFABP was elevated ~181 pg/mL after exposure to 31°C (P=0.07), and by ~378 pg/mL (P<0.

Short-Term Warm-Water Immersion for Improving Whole-Body Heat Loss in Older Men.

Purpose: Exercise-induced heat acclimation can mitigate age-related reductions in heat-loss capacity, though performing repeated bouts of strenuous exercise in the heat may be untenable for many older adults. While short-term passive heat acclimation (e.g.

Surviving the 2021 heat dome with schizophrenia: A qualitative, interview-based unpacking of risks and vulnerabilities.

This study explores the multifaceted challenges experienced by individuals with schizophrenia during extreme heat, highlighting the interplay between individual factors, social dynamics, and environmental influences. Despite making up only 1% of the Canadian population, individuals diagnosed with schizophrenia comprised 16% (n = 97) of the deaths during the 2021 heat dome in Western Canada. However, to date, there exists scant qualitative research that explore the direct experiences and the intricacies of intersecting factors faced by individuals with schizophrenia during extreme heat events.

A psychological model of predictive factors of distress following long COVID.

Background: Long COVID, described as "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection", is estimated to affect at least 10-20 % of all cases of acute SARS-CoV-2 infection. Because of its novelty, information regarding the experience of Long COVID is still emerging.

Methods: This study examines psychological distress in two long COVID populations, and their experience of fatigue, cognitive failures, experiential avoidance, rumination, and perceived injustice.

Separate and combined blockades of α- and β-adrenergic receptors in forearm sweating induced by adrenergic agents and exercise in the heat in young adults.

The assessment of adrenergic modulation of sweating as assessed via pharmacologic administration of α- and β-adrenergic receptor blockers during exercise has yielded mixed findings. However, the underlying mechanisms for this disparity remain unresolved. We investigated the effects of separate and combined blockade of α- and β-adrenergic receptors on forearm sweating induced by a 30-min moderate-intensity exercise bout ( = 17, ) and the administration of adrenergic agonists epinephrine and norepinephrine ( = 16, ) in the heat.

A Content Analysis of Web-Based Heat Stress Materials Published by Occupational Health and Safety Ministries, Associations, and Agencies in Canada.

An ever-increasing number of workplaces are becoming heat-exposed due to rising temperature extremes. However, a comprehensive review of Canadian safety materials available to support workplaces in managing this critical hazard has not previously been conducted. We undertook a review and a content analysis of heat stress materials on safety-based ministry, association, and agency websites in Canada (n = 155) to identify content related to heat stress (n = 595).

The effect of high-intensity exercise in temperate and hot ambient conditions on autophagy and the cellular stress response in young and older females.

The process of autophagy is vital in maintaining normal cellular function, especially during exposure to elevated states of physiological stress associated with exercise and hot ambient temperatures. Although prior observations are primarily limited to responses in males, the autophagic response to acute physiological stress in females represents a considerable knowledge gap. Therefore, we assessed autophagy and related pathways of cellular stress in peripheral blood mononuclear cells (PBMCs) from 20 healthy young [ = 10, mean (SD): aged 23 yr (3)] and older [ = 10, aged 69 yr (3)] females in response to 30 min of semi-recumbent high-intensity cycling exercise (70% of predetermined maximal oxygen consumption) in temperate (25°C) and hot (40°C) ambient conditions (15% relative humidity).

The Effect of 7-Day Cold Water Acclimation on Autophagic and Apoptotic Responses in Young Males.

While cold acclimation can enhance thermoregulation in humans, the potential to improve cellular cold tolerance remains unknown. Thus, this work aims to evaluate the effect of a 7-day cold-water acclimation on the cytoprotective mechanism of autophagy in young males. Further, this work assesses changes in cellular cold tolerance by employing hypothermic ex vivo (whole blood) cooling prior to and following acclimation.

Foot immersion with and without neck cooling reduces self-reported environmental symptoms in older adults exposed to simulated indoor overheating.

While foot immersion and neck cooling have been recommended for protecting heat-vulnerable groups, recent evidence does not support their efficacy for mitigating increases in physiological heat strain in older adults. However, their influence on self-reported environmental symptoms and mood-state remains unclear. Seventeen older adults (nine females, median [interquartile range] age: 72 [69-74]) completed three randomized heat exposures (6-h; 38°C, 35% relative humidity) with no cooling (control), foot immersion to mid-calf in 20°C water for the final 40-min of each hour (foot immersion), or foot immersion with a wet towel (20°C) around the neck (foot immersion with neck cooling).

Practical Considerations for Using Personal Cooling Garments for Heat Stress Management in Physically Demanding Occupations: A Systematic Review and Meta-Analysis Using Realist Evaluation.

Introduction: Due to rising temperature extremes, workplaces are seeking new solutions, such as using personal cooling garments (PCG) to mitigate and manage workplace heat exposure. This systematic review sought to assess the physiological and perceptual effects of PCGs on workers in standard work clothing performing moderate-to-heavy intensity tasks in hot environments.

Methods: A peer-reviewed search strategy was conducted in MEDLINE, Embase, CINAHL, Scopus, Global Health, and Business Source Complete with no language or time limits.

Agreement between measured and self-reported physiological strain in young adults and older adults with and without common chronic diseases during simulated occupational heat stress.

While monitoring physiological strain is recommended to safeguard workers during heat exposure, it is logistically challenging. The perceptual strain index (PeSI) is a subjective estimate thought to reflect the physiological strain index (PSI) that requires no direct monitoring. However, advanced age and chronic diseases (hypertension/type 2 diabetes [T2D]) influence the perception of heat stress, potentially limiting the utility of the PeSI.

Brain-derived neurotrophic factor in older adults exposed to simulated indoor overheating.

Purpose: Brain-derived neurotrophic factor (BDNF) is a neuroprotective growth factor that increases in young adults during short, intense bouts of passive heat stress. However, this may not reflect the response in heat-vulnerable populations exposed to air temperatures more consistent with indoor overheating during hot weather and heatwaves, especially as the BDNF response to acute stressors may diminish with increasing age. We therefore evaluated the ambient and body temperature-dependent responses of BDNF in older adults during daylong passive heating.

Robust and persistent B-cell responses following SARS-CoV-2 vaccine determine protection from SARS-CoV-2 infection.

Introduction: A clear immune correlate of protection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has not been defined. We explored antibody, B-cell, and T-cell responses to the third-dose vaccine and relationship to incident SARS-CoV-2 infection.

Methods: Adults in a prospective cohort provided blood samples at day 0, day 14, and 10 months after the third-dose SARS-CoV-2 vaccine.

Effect of cold beverages on whole-body heat exchange in young and older males during intermittent exercise in the heat.

Background: To mitigate health risks associated with occupational heat stress, workers are advised to adhere to a work-rest regimen, and hydrate regularly. However, it remains unclear if beverage temperature influences whole-body heat exchange during work-rest cycles, and if responses differ in older workers who have a blunted heat loss capacity.

Methods: Ten young (mean [SD]: 22 [3] years) and 10 older (60 [4] years) males performed four 15-min bouts of moderate-intensity cycling at a fixed rate of metabolic heat production (200 W·m), each interspersed by 15-min rest in dry heat (40°C, ~12% relative humidity).

Self-reported immune status and COVID-19 associated subjective cognitive functioning in post-COVID-19 syndrome: Examination of an Irish cohort.

Introduction: Cognitive changes are very frequently reported by people with post-COVID-19 syndrome (PCS), but there is limited understanding of the underpinning mechanisms leading to these difficulties. It is possible that cognitive difficulties are related to immune status and/or low mood. The aim of the present study was to examine the relationship between immune status and cognitive functioning in PCS, while considering whether depression symptoms also influence this association.

An exploratory investigation of heart rate and heart rate variability responses to daylong heat exposure in young and older adults.

Heart rate variability (HRV) has shown potential as a tool for monitoring thermal strain, but there is limited data to support its efficacy in older adults during prolonged heat exposures. We compared HRV between young (19-31 years,  = 20) and older (61-78 years,  = 39) adults during 9 h of heat exposure (40 °C, 9% RH). We also explored whether heart rate (HR) and/or HRV could be used to distinguish older adults who achieved elevated thermal strain, defined as either (1) an increase in core temperature >1.

Media-Based Post-Event Impact Analysis of the 2021 Heat Dome in Canada.

The unprecedented 2021 Heat Dome caused wide-ranging and long-lasting impacts in western Canada, including 619 confirmed heat-related deaths in British Columbia, a doubling of emergency medical calls, increased hospitalisations, infrastructure failures and stress on plants and animals. However, such varied socio-economic consequences of extreme heat can be challenging to capture using a single post-event analysis method. Therefore, there is a need to explore alternative approaches and data sources.

Head and neck cooling enhance exercise tolerance in individuals with multiple sclerosis.

Background: Individuals with Multiple Sclerosis (MS) experience impairments in heat dissipation, compromising core temperature regulation during exercise.

Objective: To examine the efficacy of combined head-and-neck cooling as administered via a commercially available cooling cap and neck wrap in mitigating increases in core temperature during exercise.

Methods: On separate days, ten (7 females) adults (46.

Modulation of cutaneous vasodilation by reactive oxygen species during local and whole body heating in young and older adults.

We evaluated reactive oxygen species (ROS) modulation of cutaneous vasodilation during local and whole body passive heating in young and older adults. Cutaneous vascular conductance normalized to maximum vasodilation (%CVC) was assessed in young and older adults (10/group) using laser-Doppler flowmetry at four dorsal forearm sites treated with ) Ringer solution (control), ) 100 µM apocynin (NADPH oxidase inhibitor), ) 10 µM allopurinol (xanthine oxidase inhibitor), or ) 10 µM tempol (superoxide dismutase mimetic), via intradermal microdialysis during local () and whole body heating (). In , forearm skin sites were set at 33°C during baseline and then progressively increased to 39°C and 42°C (30 min each).

Responding to the Heat and Planning for the Future: An Interview-Based Inquiry of People with Schizophrenia Who Experienced the 2021 Heat Dome in Canada.

People with schizophrenia have died at disproportionately higher rates during recent extreme heat events (EHEs) in Canada, including the deadly 2021 Heat Dome in British Columbia (B.C.).

Indoor overheating: A review of vulnerabilities, causes, and strategies to prevent adverse human health outcomes during extreme heat events.

The likelihood of exposure to overheated indoor environments is increasing as climate change is exacerbating the frequency and severity of hot weather and extreme heat events (EHE). Consequently, vulnerable populations will face serious health risks from indoor overheating. While the relationship between EHE and human health has been assessed in relation to outdoor temperature, indoor temperature patterns can vary markedly from those measured outside.