
Leonidas G. IoannouJožef Stefan Institute | IJS · Department of Automatics, Robotics and biocybernetics
Leonidas G. Ioannou
BSc (Hons), MSc, dual PhD
Investigating the effects of environment on human occupation, health, physiology, cognition, and productivity.
About
71
Publications
19,862
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,448
Citations
Introduction
Leonidas research focuses on the effects of different environmental factors on human occupation, health, and physiology. He participated in several European and international projects where he had the opportunity to collect field/lab data across many countries around the globe, leading to the development of national and international legislations. He has previously collaborated with reputable organizations, including the WHO, ILO, and ESA on projects aiming to enhance human health and wellbeing.
Additional affiliations
February 2020 - December 2020
April 2016 - March 2017
December 2014 - present
Education
November 2016 - January 2020
February 2016 - January 2020
September 2014 - February 2016
Publications
Publications (71)
Climate change has resulted in an increase in heat exposure globally. There is strong evidence that this increased heat stress is associated with poor maternal and fetal outcomes, especially in vulnerable populations. However, there remains poor understanding of the biological pathways and mechanisms involved in the impact of heat in pregnancy. Thi...
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-mi...
Background: Migrant construction workers involved in building infrastructure for mega-sporting events face elevated risks of illness and death. However, specific health outcomes for these workers have not been systematically reviewed, limiting opportunities to identify and address their challenges. Methods: This study systematically reviewed health...
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 task...
Climate change has resulted in an increase in heat exposure globally. There is strong evidence that this increased heat stress is associated with poor maternal and fetal outcomes, especially in vulnerable populations. However, there remains poor understanding of the biological pathways and mechanisms involved in the impact of heat in pregnancy. Thi...
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 diabet...
We previously developed the FAME Lab PHS software (PHSFL), a free offline software to calculate the predicted heat strain for a group of individuals based on the ISO 7933. The objectives of this study were to: upgrade the PHSFL from an offline (desktop-version) tool to a web-based platform, as well as assess its validity in recreational athletes in...
Introduction
During heatwaves, it is important to monitor workers’ cardiovascular health since 35% of those working in hot environments experience symptoms of heat strain. Wearable technology has been popularized for monitoring heart rate (HR) during recreational activities, but it can also be used to monitor occupational heat strain based on core...
Introduction
Climate change increases not only the frequency, intensity and duration of extreme heat events but also annual temperatures globally, resulting in many negative health effects, including harmful effects on pregnancy and pregnancy outcomes. As temperatures continue to increase precipitously, there is a growing need to understand the und...
Introduction
Heat-Shield was funded by the European Commission to mitigate the health and productivity effects of occupational heat stress on European workers.
Materials and Methods
The project involved 20 partners from 11 European countries working together during 2016-2022. Most of these partners still work together to address occupational heat...
This study investigated the impact of a multiday heatwave on nocturnal physiology, behavior, and sleep under controlled conditions with comprehensive monitoring of environmental factors and participant activities. Seven young healthy males were confined for 10 days in controlled conditions that ranged between hot-to-warm (day: 35.4 °C, night: 26.3...
This study aimed to investigate seasonal heat acclimatization in active adolescents following summer. Fifteen (5 females) active adolescents (14.6 ± 1.0 y) completed a 45-min heat response test (HRT) walking at 60% V˙O2peak in 40°C and 30% relative humidity before and after summer (i.e. November 2022 and March 2023). During the HRT, gastro-intestin...
Rationale
Monitoring physiological strain is recommended to safeguard workers during heat exposure, but is logistically challenging. The perceptual strain index (PeSI) is a subjective estimate thought to reflect the physiological strain index (PSI) that requires no physiological monitoring. However, sex is known to influence perceptions of heat str...
Background
Athletes and military personnel are often expected to compete and work in hot and/or humid environments, where decrements in performance and an increased risk of exertional heat illness are prevalent. A physiological strategy for reducing the adverse effects of heat stress is to acclimatise to the heat.
Objective
The aim of this systema...
Introduction: This study examined the impact of different upper-torso sportswear
technologies on the performance and physiological heat strain of well-trained
and national-level athletes during prolonged running in moderately hot
conditions.
Methods: A randomized crossover design was employed in which 20 well-trained
(n = 16) and national-level (n...
Occupational heat stress protection framework.
Extreme heat events directly impact worker health and cause additional cascading and transitional workplace impacts. However, current investigations on these impacts often rely on specific datasets (e.g., compensation claims, hospitalizations). Thus, to continue to work towards preventing and mitigating the occupational risks posed by extreme heat...
Background: Prevention plays a key role in ensuring health and safety and is particularly important in scenarios when life is threatened. Adverse thermal conditions are experienced by billions of people daily, affecting the human capacity for thermoregulation and increasing the risks of life-threatening accidents, diseases, and fatalities. The aim...
Introduction: This study investigated the impact of the multistage ultra-marathon event ''Marathon des Sables'' (MdS) performed in the Sahara Desert on the psychophysical capacity of an athlete. Methods: We collected and analyzed environmental, physiological, and behavioral data from a 39-year-old athlete who participated in the MdS. Specifically,...
Objective: Endothelial function, the ability of cells of the vascular endothelial wall to secrete compounds, is linked with metabolic and cardiovascular disease risks. One of the most well-known noninvasive tests used to assess skin vascular reactivity as a measure of endothelial function is the reactive hyperemic response test (RHRT). However, the...
The present observational study was conducted to uncover potential differences in the risk of experiencing high occupational heat strain during agriculture work between migrants and their native coworkers, as well as to elucidate the factors that may contribute to such differences. The study took place over the period from 2016 through 2019 and inv...
Purpose
This study examined physiological and perceptual parameters related to cold-induced vasodilation (CIVD) in the fingers and toes of people with paraplegia and compared them with responses observed in able-bodied individuals.
Methods
Seven participants with paraplegia and seven able-bodied individuals participated in a randomized matched-con...
Introduction: A wide range of cooling vests for heat-strain mitigation purposes during physical work are available on the market. The decision regarding the optimal cooling vest/concept for a specific environment can be challenging by relying solely on the information provided by the manufacturers. The aim of this study was to investigate how diffe...
Global warming has caused an increase in the frequency, duration, and intensity of summer heatwaves (HWs). Prolonged exposure to hot environments and orthostasis may cause conflicting demands of thermoregulation and blood pressure regulation on the vasomotor system, potentially contributing to cardiovascular complications and occupational heat stra...
Background:
Chilblains/perniosis is a non-freezing cold injury causing painful inflammatory skin lesions. Its pathogenesis remains poorly understood because it is often studied as secondary to other underlying conditions.
Methods:
We systematically investigated the population characteristics, symptoms, and predisposing factors of chilblains in h...
While exercise benefits a wide spectrum of diseases and affects most tissues and organs, many aspects of its underlying mechanistic effects remain unsolved. In vitro exercise, mimicking neuronal signals leading to muscle contraction in vitro, can be a valuable tool to address this issue. Following the Preferred Reporting Items for Systematic Review...
Temperature and the affiliated scientific community are a leading forum for discussion and dissemination of scientific evidence relevant to the societal challenges of global warming.
Background
Physiological heat adaptations can be induced following various protocols that use either artificially controlled (i.e. acclimation) or naturally occurring (i.e. acclimatisation) environments. During the summer months in seasonal climates, adequate exposure to outdoor environmental heat stress should lead to transient seasonal heat accli...
Cancer is a set of diseases characterized by several hallmark properties, such as increased angiogenesis, proliferation, invasion, and metastasis. The increased angiogenic activity constantly supplies the tumors with nutrients and a plethora of cytokines to ensure cell survival. Along these cytokines is a newly discovered protein, called irisin, wh...
In a series of three companion papers published in this Journal, we identify and validate the available thermal stress indicators (TSIs). In this first paper of the series, we conducted a systematic review (registration: INPLASY202090088) to identify all TSIs and provide reliable information regarding their use (funded by EU Horizon 2020; HEAT-SHIE...
Global warming has caused an increase in the frequency, duration, and intensity of summer heatwaves (HW). Prolonged exposure to hot environments and orthostasis may cause conflicting demands of thermoregulation and blood pressure regulation on the vasomotor system, potentially contributing to cardiovascular complications and occupational heat strai...
Background:
Cold-induced vasodilation (CIVD) is a phenomenon that refers to a paradoxical increase in finger temperature that sometimes occurs during cold exposure. The aim of this study was to compare CIVD responses between women and men, during exposure to different environmental conditions.
Methods:
Seven men and seven women participated in a...
Occupational Health and Safety (OHS) is an interdisciplinary field that addresses almost
all human activities. The various specialized and highly demanding OHS issues like, for
example, mechanical vibrations, electromagnetic fields (EMF), artificial optical radiation
(AOR), chemical and biological agents, are covered at European and Hellenic level...
Objective:
We examined whether different intensities of exercise and/or physical activity (PA) levels affected and/or associated with vaccination efficacy.
Methods:
A systematic review and meta-analysis was conducted and registered with PROSPERO (CRD42021230108). The PubMed, EMBASE, Cochrane Library (trials), SportDiscus, and CINAHL databases we...
The present comprehensive review (i) summarizes the current knowledge on the impacts of occupational heat stress on outdoor workers, (ii) provides a historical background on this issue, (iii) presents a meta-analysis of published data, (iv) explores inter-individual and intra-individual factors, (v) discusses the available heat mitigation strategie...
In a series of three companion papers published in this Journal, we identify and validate the available thermal stress indicators (TSIs). In this third paper, we conducted field experiments across nine countries to evaluate the efficacy of 61 meteorology-based TSIs for assessing the physiological strain experienced by individuals working in the hea...
In a series of three companion papers published in this Journal, we identify and validate the
available thermal stress indicators (TSIs). In this second paper of the series, we identified the
criteria to consider when adopting a TSI to protect individuals who work in the heat, and we
weighed their relative importance using a Delphi exercise with 20...
There is a need to rapidly screen individuals for heat strain and fever using skin temperature (Tsk) as an index of deep body temperature (Tb). This study’s aim was to assess whether Tsk could serve as an accurate and valid index of Tb during a simulated heatwave. Seven participants maintained a continuous schedule over 9-days, in 3-day parts; pre-...
Previous field studies monitoring small groups of participants showed that heat stress in the electrical utilities industry may be detrimental to worker health and safety. Our aim in this study was to characterize heat stress and strain in electrical utilities workers across North America. A total of 428 workers in the power generation, transmissio...
Introduction: This study evaluated how single or combinations of weather parameters (temperature, humidity, wind speed, solar load) affect peak performance during endurance running events and identify which events are most vulnerable to varying weather conditions.
Methods: Results for the marathon, 50km race-walk, 20km race-walk, 10,000m, 5,000m an...
Ambient temperature can affect the survival rate of humans. Studies have shown a relationship between ambient temperature and mortality rate in hot and cold environments. This effect of ambient temperature on mortality seems to be more pronounced in older people. The aim of this study is to examine the effects of thermal stress on cardiovascular mo...
Heat strain impairs performance across a broad spectrum of sport disciplines. The impeding effects of hyperthermia and dehydration are often ascribed to compromised cardiovascular and muscular functioning, but expert performance also depends on appropriately tuned sensory, motor and cognitive processes. Considering that hyperthermia has implication...
Rising environmental temperatures have become a growing challenge for societies across the globe (World Health
Organization, 2014; Flouris and Kenny, 2017; Nybo et al., 2017), and extreme heat events result in the highest shortterm
rise in morbidity and mortality when compared with all other natural weather hazards (Borden and Cutter, 2008;
Luber a...
Data suggest migrant construction workers are at risk of work related ill health, injury, and death, but better evidence to inform policy making and improve their health is needed, say Andreas Flouris and colleagues
Background:
A set of four case-control (n = 109), randomized-controlled (n = 7), cross-sectional (n = 78), and intervention (n = 47) studies was conducted across three countries to investigate the effects of sun exposure on worker physiology and cognition.
Methods:
Physiological, subjective, and cognitive performance data were collected from peo...
Background:
Occupational heat exposure can provoke health problems that increase the risk of certain diseases and affect workers' ability to maintain healthy and productive lives. This study investigates the effects of occupational heat stress on workers' physiological strain and labor productivity, as well as examining multiple interventions to m...
Purpose:
We investigated the environmental conditions in which all outdoor International Tennis Federation (ITF) junior tournaments (athlete ages: <18 y) were held during 2010-2019. Thereafter, we performed a crossover trial (ClinicalTrials.gov: NCT04197375) assessing the efficacy of head-neck precooling for mitigating the heat-induced psychophysi...
Background:
The aim of the study was to investigate the effect of a simulated heat-wave on the labour productivity and physiological strain experienced by workers.
Methods:
Seven males were confined for ten days in controlled ambient conditions. A familiarisation day was followed by three (pre, during, and post-heat-wave) 3-day periods. During e...
Objectives:
To provide perspectives from the HEAT-SHIELD project (www.heat-shield.eu): a multi-national, inter-sectoral, and cross-disciplinary initiative, incorporating twenty European research institutions, as well as occupational health and industrial partners, on solutions to combat negative health and productivity effects caused by working on...
Successful implementation of cooling strategies obviously depends on identifying effective interventions, but in industrial settings, it is equally important to consider feasibility and economic viability. Many cooling interventions are available, but the decision processes affecting adoption by end-users are not well elucidated. We therefore arran...
White adipose tissue (WAT) thermogenic activity may play a role in whole-body energy balance and two of its main regulators are thought to be environmental temperature (Tenv) and exercise. Low Tenv may increase uncoupling protein one (UCP1; the main biomarker of thermogenic activity) in WAT to regulate body temperature. On the other hand, exercise...
Health and performance impairments provoked by thermal stress are societal challenges geographically spreading and intensifying with global warming. Yet, science may be underestimating the true impact, since no study has evaluated effects of sunlight exposure on human brain temperature and function. Accordingly, performance in cognitively dominated...
Summary of key findings from a report prepared by the FAME Laboratory for the International Labour Organization, the Qatar Ministry of Administrative Development, Labour and Social Affairs, and the Supreme Committee for Delivery and Legacy.
Aim: Warm-up activates muscular thermogenesis leading to enhanced athletic performance and reduced risk for exercise-induced injuries. However, very little is known about the thermo physiological responses of elite basketball players during the time spent on bench (BENCH) and consequently its impact on athletic performance in cool environments. The...
AIM: Cold exposure and exercise may increase thermogenic capacity of white adipose tissue (WAT), which could subsequently enhance energy expenditure and body weight loss. [...]
Our primary objective in this study was to design and implement the FAME Lab PHS Calculator software (PHSFL) (www.famelab.gr/research/downloads), a free tool to calculate the predicted heat strain of an individual based on ISO 7933:2018. Our secondary objective was to optimize the practicality of the PHSFL by incorporating knowledge from other ISO...
Background:
Occupational heat strain (ie, the effect of environmental heat stress on the body) directly threatens workers' ability to live healthy and productive lives. We estimated the effects of occupational heat strain on workers' health and productivity outcomes.
Methods:
Following PRISMA guidelines for this systematic review and meta-analys...
Purpose
To evaluate the prevalence of dehydration in occupational settings and contextualize findings to effects on performance in cognitively dominated tasks, simple and complex motor tasks during moderate and high heat stress.
Methods
The study included an occupational part with hydration assessed in five industries across Europe with urine samp...