Body Heat Research Articles

Numerical study on the onset of global-scale flow from individual buoyant plumes: Implications for indoor disease transmission

Transport of exhaled droplets and aerosol suspension is a main route for the transmission of highly infectious respiratory diseases. A poorly ventilated room, where human body heat drives the flow and the pathogen motion, is one such paradigmatic situation with an elevated risk of viral transmission. Here, we report a numerical study on human body heat-driven buoyancy convection in a slender rectangular geometry with the geometric size of 12 × 1 × 3 m3. Using large-scale three-dimensional simulations, we reveal how different spacings between human body heat sources can potentially spread pathogenic species between occupants in a room. Morphological transition in airflow takes place as the distance between human heat sources is varied, which shapes distinct patterns of disease transmission: For sufficiently large distance, individual buoyant plume creates a natural barrier, forming buoyant jets that block suspension spread between occupants. Thermal plumes exhibit significant individual effects. However, for small distances, a collective effect emerges and thermal plumes condense into superstructure, facilitating long-distance suspension transport via crossing between convection rolls. In addition, we quantify the impact of morphological transition on the transport of viral particles by introducing tracer particles. The quantitative analysis shows that under certain critical distances, the infection risk becomes significantly elevated due to this transition and collective behavior. Our findings highlight the importance of reasonable social distancing to reduce indoor cross-transmission of viral particles between people and provide new insights into the hidden transitional behavior of pathogen transmission in indoor environments.

A review on transdermal drug delivery system

Drugs that are applied topically are delivered using transdermal drug delivery devices. These are pharmaceutical preparations of varying sizes, containing one or more active ingredients, intended to be applied to the unbroken skin in order to deliver the active ingredient after passing through the skin barriers, and these avoid first pass metabolism. Today about 74% of drugs are taken orally and are not found effective as desired. To improve efficacy transdermal drug delivery system was emerged. A notable advantage of transdermal drug delivery compared to other methods like oral, topical, intravenous (IV), and intramuscular (IM) administration is its controlled release of medication into the patient's system. This controlled release is achieved either by using a porous membrane enclosing a medication reservoir or by utilizing the patient's body heat to melt thin layers of medication embedded in the adhesive. Despite its benefits, transdermal drug delivery has certain limitations due to the skin's effective barrier function. Only molecules with small sizes can efficiently permeate the skin and consequently be delivered through this method.

Enhanced conductive body heat loss during sleep increases slow-wave sleep and calms the heart

Substantial evidence suggests that the circadian decline of core body temperature (CBT) triggers the initiation of human sleep, with CBT continuing to decrease during sleep. Although the connection between habitual sleep and CBT patterns is established, the impact of external body cooling on sleep remains poorly understood. The main aim of the present study is to show whether a decline in body temperatures during sleep can be related to an increase in slow wave sleep (N3). This three-center study on 72 individuals of varying age, sex, and BMI used an identical type of a high-heat capacity mattress as a reproducible, non-disturbing way of body cooling, accompanied by measurements of CBT and proximal back skin temperatures, heart rate and sleep (polysomnography). The main findings were an increase in nocturnal sleep stage N3 (7.5 ± 21.6 min/7.5 h, mean ± SD; p = 0.0038) and a decrease in heart rate (− 2.36 ± 1.08 bpm, mean ± SD; p < 0.0001); sleep stage REM did not change (p = 0.3564). Subjects with a greater degree of body cooling exhibited a significant increase in nocturnal N3 and a decrease in REM sleep, mainly in the second part of the night. In addition, these subjects showed a phase advance in the NREM-REM sleep cycle distribution of N3 and REM. Both effects were significantly associated with increased conductive inner heat transfer, indicated by an increased CBT- proximal back skin temperature -gradient, rather than with changes in CBT itself. Our findings reveal a previously far disregarded mechanism in sleep research that has potential therapeutic implications: Conductive body cooling during sleep is a reliable method for promoting N3 and reducing heart rate.

Touch-activated information interaction system based on body-heat-powered flexible thermoelectric generator for food spoilage monitoring

With the rapid advancement of the Internet of Things, a wide range of information interaction platforms have been developed to enhance the quality of life and work. Nevertheless, rigid batteries greatly limit its development, which requires frequent replacement or recharge. Thermoelectric generators (TEG) have emerged as an attractive form for energy suppliers owing to their ability to convert low-grade energy heat into sustainable electricity. Herein, we have implemented a flexible TEG-based multifunctional information interaction system, which utilizes body heat to enable information interaction through finger touch. To increase the efficiency of energy conversion, the flexible TEG achieves high performance by optimizing the filling factor and material thermal conductivity, leading to a normalized power density of 1.43 μW/cm2 K2. As a proof-of-concept demonstration, the system has been applied to food spoilage monitoring with an MXene-based sensor to achieve stable and sensitive ammonia detection. The TEG-based information interaction system provides an attractive solution for intelligent packaging and will act as an exciting platform for human body energy harvesting and human–machine interaction for point of care testing.

A pH-Sensitive Stretchable Zwitterionic Hydrogel with Bipolar Thermoelectricity.

Amid growing interest in using body heat for electricity in wearables, creating stretchable devices poses a major challenge. Herein, a hydrogel composed of two core constituents, namely the negatively-charged 2-acrylamido-2-methylpropanesulfonic acid and the zwitterionic (ZI) sulfobetaine acrylamide, is engineered into a double-network hydrogel. This results in a significant enhancement in mechanical properties, with tensile stress and strain of up to 470.3kPa and 106.6%, respectively. Moreover, the ZI nature of the polymer enables the fabrication of a device with polar thermoelectric properties by modulating the pH. Thus, the ionic Seebeck coefficient (Si) of the ZI hydrogel ranges from -32.6 to 31.7mV K-1 as the pH is varied from 1 to 14, giving substantial figure of merit (ZTi) values of 3.8 and 3.6, respectively. Moreover, a prototype stretchable ionic thermoelectric supercapacitor incorporating the ZI hydrogel exhibits notable power densities of 1.8 and 0.9mW m-2 at pH 1 and 14, respectively. Thus, the present work paves the way for the utilization of pH-sensitive, stretchable ZI hydrogels for thermoelectric applications, with a specific focus on harvesting low-grade waste heat within the temperature range of 25-40 °C.

High figure-of-merit of single-walled carbon nanotubes films with metallic type conduction

Carbon nanotubes are promising candidates for thermoelectric power generation because of their one-dimensionality mediated high Seebeck coefficient, high electrical conductivity with added advantages of flexibility, light weight, and scalability. We report the temperature-dependent thermoelectric properties of single-walled carbon nanotube (SWCNTs) films. The SWCNTs films exhibit p-type metallic conduction with high Seebeck coefficient (∼69.5 μVK−1) and moderate electrical conductivity (∼76 Scm−1). The films exhibit low thermal conductivity (∼0.1 Wm−1 K−1) due to phonon scattering at the interjunction region. The synergetic combination of thermoelectric properties resulted in a high figure-of-merit of ∼0.11 at 305 K. A flexible thermoelectric generator based on SWCNTs films mounted on a curved hot surface exhibited an output of 17 mV and 54 μA under a small temperature gradient of 10 K. The present work provides possible avenues for developing wearable SWCNTs based thermoelectric power generation modules for harvesting body heat.

Hormonal intrauterine devices and heat exchange during exercise.

Synthetic progestins in oral contraceptives are thought to blunt heat dissipation by reducing skin blood flow and sweating. However, whether progestin-releasing intrauterine devices (IUDs) modulate heat loss during exercise-heat stress is unknown. We used direct calorimetry to measure whole-body total (dry + evaporative) heat loss in young, physically active women (mean (SD); aged 24(4)years, 39.3(5.3) ml/kg/min) with (IUD; n=19) and without (Control; n=17) IUDs in the follicular and luteal phases of the menstrual cycle during light- and moderate-intensity exercise at fixed rates of heat production (∼175 and ∼275W/m2 ) in 30°C, ∼21% relative humidity. Between-group and -phase differences were evaluated using traditional hypothesis testing and statistical equivalence testing within pre-determined bounds (±11W/m2 ; difference required to elicit a ±0.3°C difference in core temperature over 1h) in each exercise bout. Whole-body total heat loss was statistically equivalent between groups within ±11Wm-2 (IUD-Control [90% CIs]; Light: -2 [-8, 5] W/m2 , P=0.007; Moderate: 0 [-6, 6] W/m2 , P=0.002), as were dry and evaporative heat loss (P ≤ 0.023), except for evaporative heat loss during moderate-intensity exercise (equivalence: P=0.063, difference: P=0.647). Whole-body total and evaporative heat loss were not different between phases (P≥0.267), but dry heat loss was 3 [95% CIs: 1, 5] W/m2 greater in the luteal phase (P≤0.022). Despite this, all whole-body heat loss outcomes were equivalent between phases (P≤0.003). These findings expand our understanding of the factors that modulate heat exchange in women and provide valuable mechanistic insight of the role of endogenous and exogenous female sex hormones in thermoregulation. KEY POINTS: Progestin released by hormonal intrauterine devices (IUDs) may negatively impact heat dissipation during exercise by blunting skin blood flow and sweating. However, the influence of IUDs on thermoregulation has not previously been assessed. We used direct calorimetry to show that IUD users and non-users display statistically equivalent whole-body dry and evaporative heat loss, body heat storage and oesophageal temperature during moderate- and high-intensity exercise in a warm, dry environment, indicating that IUDs do not appear to compromise exercise thermoregulation. However, within IUD users and non-users, dry heat loss was increased and body heat storage and oesophageal temperature were reduced in the luteal compared to the follicular phase of the menstrual cycle, though these effects were small and unlikely to be practically meaningful. Together, these findings expand our understanding of the factors that modulate heat exchange in women and have important practical implications for the design of future studies of exercise thermoregulation.

Thermal-to-Electrical Conversion Based on Salinity Gradient Driven by Evaporation.

Constructing concentration differences between anions and cations at the ends of an ionic conductor is an effective strategy in electricity generation for powering wearable devices. Temperature gradient or salinity gradient is the driving force behind such devices. But their corresponding power generation devices are greatly limited in actual application due to their complex structure and harsh application conditions. In this study, a novel ionic concentration gradient electric generator based on the evaporation difference of the electrolyte is proposed. The device can be constructed without the need for semipermeable membranes, and operation does not need to build a temperature difference. As a demonstration, a PVA-Na ionic hydrogel is prepared as an electrolyte for the device and achieved a thermovoltage of more than 200mV and an energy density of 77.94 J m-2 at 323 K. Besides, the device exhibits the capability to sustain a continuous voltage output for a duration exceeding 1500min, as well as enabling charging and discharging cycles for 100 iterations. For practical applications, a module comprising 16 sub-cells is constructed and successfully utilized to directly power a light-emittingdiode. Wearable devices and their corresponding cell modules are also developed to recycle body heat.

Review on Transdermal Drug Delivery System

A transdermal drug is an adhesive patch with a prescription that is applied to the skin in order to penetrate the epidermis and enter the bloodstream. This frequently encourages the body's wounded area to mend. A benefit of a topical medicationThe advantage of this delivery method over oral, topical, intravenous, intramuscular, etc. medication delivery is that the patch allows for a controlled release of medication into the patient. This is typically achieved by either a porous membrane covering a medication reservoir or by body heat melting thin layers of medication embedded in the adhesive. Transdermal medication delivery allows for a consistent blood level profile, which minimizes systemic side effects, regulated drug release into the patient

Improvisation in wicking property of flexible polyurethane foams by adding bamboo and gelatin fillers

PU foam is one of the softest, most easily accessible, and affordable mattress materials. In PU foam, wider pores and a more open-cell structure have both advantages and drawbacks. Despite having fewer cells PU foam does not control airflow very effectively and commonly faces criticism for causing body heat and for retaining moisture. A warm, humid climate because of stored body moisture and sweat functions as a haven for bacteria and germs and encourages the proliferation of dust mites contributing to excessive odour and allergic reactions. This study aims to investigate the impact of bamboo and gelatin filler dosage or loading on the wicking property of the foam by using a discontinuous foaming process. Foams with gelatin and bamboo fillers were prepared at 2, 4, and 8% by weight concentrations, respectively, along with a standard 32-density foam without filler. A comparative study was conducted on the effect of increasing filler content on the wicking and mechanical properties of the foam. The wicking and porosity levels of bamboo-filled foam were higher than standard foam and gelatin-loaded foam. With increasing concentrations of bamboo filler, a rapid increase in foam wicking by 7–10 mm was noted. However, an increase in gelatin filler concentration resulted in an increase in foam porosity and elongation with a slight improvement in wicking ability. Improvisation in the wicking property of the foam was observed with dosage increment of bamboo filler. According to this research findings, the bamboo powder can be utilized as a filler to enhance wicking properties in flexible polyurethane foam.

Subjective sleep onset latency is influenced by sleep structure and body heat loss in human subjects.

The present study examined the relationship between subjective sleep onset latency (SOL), sleep structure, changes in skin and body temperature, and subjective evaluation of sleep in healthy young adults to elucidate the pathophysiological mechanisms of insomnia. A total of 28 participants (age 21.54 [0.50] years) with no sleep problems participated in a 1-h polysomnographic recording that obtained objective sleep parameters during the daytime while skin and body temperatures were recorded. The distal-proximal skin temperature gradient (DPG) was calculated. Subjective parameters, such as subjective SOL, sleep time, and restorative sleepiness, were evaluated before and after sleep. Most participants estimated their sleep latency as being longer than their actual SOL (13.7 versus 7.6 min). Objective SOL was significantly correlated with each sleep stage parameter whereas subjective SOL was negatively correlated with Stage N2 sleep duration (Rho = -0.454, p = 0.020), slow-wave activity and delta power (Rho = -0.500, p = 0.011 and Rho = -0.432, p = 0.031, respectively), and ΔDPG (the degree of reduction of heat loss before and after lights-off). Stepwise regression analysis showed that ΔDPG was the strongest predictive factor in explaining the length of subjective SOL. The degree of heat dissipation before and after lights-off contributed most to the sensation of falling asleep in healthy young adults. This finding may be helpful for elucidating the physiological mechanisms of insomnia and its treatment.

Thermoelectrically Driven Dual-Mechanism Regulation on SERS and Application Potential for Rapid Detection of SARS-CoV-2 Viruses and Microplastics.

Electric-induced surface-enhanced Raman scattering (E-SERS) has been widely studied for its flexible regulation of SERS after the substrate is prepared. However, the enhancement effect is not sufficiently high in the E-SERS technology reported thus far, and no suitable field of application exists. In this study, a highly sensitive thermoelectrically induced SERS substrate, Ag/graphene/ZnO (AGZ), was fabricated using ZnO nanoarrays (NRs), graphene, and Ag nanoparticles (NPs). Applying a temperature gradient to the ZnO NRs enhanced the SERS signals of the probe molecules by a factor of approximately 20. Theoretical and experimental results showed that the thermoelectric potential enables the simultaneous modulation of the Fermi energy level of graphene and the plasma resonance peak of Ag NPs, resulting in a double enhancement in terms of physical and chemical mechanisms. The AGZ substrate was then combined with a mask to create a wearable thermoelectrically enhanced SERS mask for collecting SARS-CoV-2 viruses and microplastics. Its SERS signal can be enhanced by the temperature gradient created between a body heat source (∼37 °C) and a cold environment. The suitability of this method for virus detection was also examined using a reverse transcription-polymerase chain reaction and SARS-CoV-2 virus antigen detection. This work offers new horizons for research of E-SERS, and its application potential for rapid detection of the SARS-CoV-2 virus and microplastics was also studied.

The demographic history and adaptation of Canarian goat breeds to environmental conditions through the use of genome-wide SNP data

BackgroundThe presence of goats in the Canary Islands dates back to the late 1st millennium BC, which coincides with the colonization by the Amazigh settlers. However, the exact geographic origin of Canarian goats is uncertain since the Amazigh peoples were distributed over a wide spatial range. Nowadays, three Canarian breeds (Palmera, Majorera and Tinerfeña) are officially recognized, along with two distinct South and North Tinerfeña ecotypes, with the South Tinerfeña and Majorera goats thriving in arid and dry semi-desertic environments and the Palmera and North Tinerfeña goats are adapted to humid and temperate areas that are influenced by trade winds. Genotypes for 224 Canarian goats were generated using the Illumina Goat single nucleotide polymorphism (SNP)50 BeadChip. By merging these data with the genotypes from 1007 individuals of African and Southern European ancestry, our aim was to ascertain the geographic origin of the Canarian goats and identify genes associated with adaptation to diverse environmental conditions.ResultsThe diversity indices of the Canarian breeds align with most of those of the analyzed local breeds from Africa and Europe, except for the Palmera goats that showed lower levels of genetic variation. The Canarian breeds demonstrate a significant genetic differentiation compared to other populations, which indicates a history of prolonged geographic isolation. Moreover, the phylogenetic reconstruction indicated that the ancestry of the Canarian goats is fundamentally North African rather than West African. The ADMIXTURE and the TreeMix analyses showed no evidence of gene flow between Canarian goats and other continental breeds. The analysis of runs of homozygosity (ROH) identified 13 ROH islands while the window-based FST method detected 25 genomic regions under selection. Major signals of selection were found on Capra hircus (CHI) chromosomes 6, 7, and 10 using various comparisons and methods.ConclusionsThis genome-wide analysis sheds new light on the evolutionary history of the four breeds that inhabit the Canary Islands. Our findings suggest a North African origin of the Canarian goats. In addition, within the genomic regions highlighted by the ROH and FST approaches, several genes related to body size and heat tolerance were identified.

Correlating Light Intensity with Body Heat Changes: Implications for Screen Time and Well-being

This study investigates the correlation between light intensity and body heat changes during screen time activities, aiming to uncover potential implications for well-being. With the pervasive use of screens in modern society, understanding how light emitted from devices affects physiological responses is crucial. The research employs a multidisciplinary approach, combining thermal imaging techniques with light intensity measurements to explore the intricate relationship between these variables. The methodology involves recruiting participants to engage in screen-based activities, such as watching television or using laptops, under controlled conditions. Thermal imaging cameras are utilized to monitor changes in body heat, providing real-time data on thermal responses. Concurrently, light intensity meters measure the brightness emitted by the screens, allowing for the quantification of light exposure levels. Data analysis encompasses statistical techniques to identify correlations between light intensity and body heat changes. Factors such as screen type, content, and viewing distance are considered to elucidate potential moderating variables. The findings aim to provide insights into how different levels of light intensity impact physiological well-being during screen time activities. Implications of the study extend to various domains, including ergonomic design, health recommendations, and screen usage guidelines. Understanding the interplay between light exposure and body heat regulation can inform the development of anti-screen technologies or interventions aimed at mitigating potential negative effects of prolonged screen time on health and well-being. Overall, this research contributes to a comprehensive understanding of the complex relationship between screen-based activities, light exposure, and human physiology

Preparation and properties of shape memory polyurethane filaments triggered by human body temperature

To utilize the human body heat to trigger the shape memory smart textiles, shape memory polyurethane filaments (SMPUF) with three different transition temperatures were prepared based on modified polycaprolactone diol (PCL) by dry spinning. The chemical structure was characterized systemically. The shape memory properties, tensile properties, resilience, and viscoelasticity were studied comprehensively. The results revealed that the phase transition temperatures were close to human body temperature which measured 19.97°C, 27.33°C, and 30.37°C, respectively. Additionally, the fraction of hydrogen bonds in the samples was about 30% less than that of polyurethane filaments (PUF). The best shape fixity ratio was 88.5% and the shape recovery ratio was 96.7% belonging to samples with a transition temperature of 30.37°C. At 55°C, the elastic recovery was 45.2% higher than that at 22°C. As the temperature rose, the elastic modulus of SMPUF decreased until it reached that of PUF. The static and dynamic viscoelasticity of SMPUF indicated that the phase transition of the soft segment affects the movement of the molecular chain. SMPUF can be used as compression garments, and wearable orthopedic devices, such as the elastic bands prepared in this work.

Engineered spectrally selective and spatially segmented emittances for infrared camouflage textiles

D-SET not only achieves effective IR camouflage but also dissipates human body heat through radiative cooling, ensuring thermal comfort, while maintaining excellent durability and breathability. IRC-SET enables IR camouflage in complex backgrounds.

Do brood parasitic Common Cuckoos develop brood patches during the breeding season?

Many birds develop brood patches on their ventral apterium under hormonal regulation to effectively transmit body heat to eggs during incubation. The developed patch has several characteristics, including de-feathering, vascularization, and edema. However, little is known about whether avian brood parasites that do not incubate their eggs exhibit brood patch development during the breeding season. In this study, we measured the size of the ventral apterium in 114 Common Cuckoos (Cuculus canorus) captured in the field throughout the breeding season and examined the appearance of the ventral apterium to confirm the development of brood patches. We also examined whether morphological traits and various factors correlated with the size of the ventral apterium (sternal apterium and abdominal apterium) and how it changed during the breeding season. We found no clear signs of brood patch development in Common Cuckoos captured throughout the breeding season, indicating that they likely did not develop brood patches on the ventral apterium during this period. We also found that ventral apterium size was positively correlated with wing length and body weight. In addition, Common Cuckoos with newly growing feathers on the boundary of the ventral apterium with pteryla were frequently observed as seasons progressed to the end. In conclusion, Common Cuckoos exhibit neither brood patch development nor the vestigial characteristics of ancestral brood patches, except for the growth of feathers on boundary the ventral apterium. Further studies examining brood patches across different groups of avian brood parasites are valuable for enhancing our understanding of the developmental and physiological adaptations of avian brood parasites.

Cold Injury Prevention and Management in High Altitude Extreme Environments Pharmacological and Therapeutical Interventions

Cold injury refers to local or systemic body response that occurs due to massive loss of body heat when the body is exposed to extremely cold temperatures. The current modalities for the prevention and management of cold injury(ies) are very limited due to the paucity of availability of targeted therapeutics. Pathophysiological cascades in cold injury include: (a) desensitization of sensory neurons can be manifest as a result of altered pathophysiological functions viz., Ca2+ imaging, calcitonin gene-related peptide release, expressions of inflammatory mediators (PGE2: prostaglandin E2, NGF: nerve growth factors), (b) inflammatory markers viz.; interleukins (IL-1β, IL-6, and IL-10), tumor necrosis factor-alpha (TNF-α), and CD62E/endothelial-leukocyte adhesion molecule 1 (E-selectin); (c) oxidative stress markers associated with cold injury measured through serum level of protein carbonyl, 4-hydroxy-2-nonenal (4-HNE), superoxide dismutase (SODs), advanced oxidative protein products (AOPP) and nitrotyrosine; (d) endothelial damage: nitric oxide (NO), prostacyclin (PGI2), reactive oxygen species (ROS), Von-Willebrand factor (VWF), CD31/PECAM-1 (platelet/endothelial cell adhesion molecule 1), CD36/SR-B3 (scavenger receptor class B member 3) and tissue-type plasminogen activator (TTPA). In this review paper, we elaborate on the current state-of-the-art pharmacological interventions for cold injury that may be beneficial in developing novel and targeted therapeutics for the prevention, management, and treatment of cold injury.

Material flow and heat transfer characteristics in flat-top laser composite arc-based directed energy deposition

In this study, a novel flat-top laser composite arc-based directed energy deposition process is proposed, and the material flow and heat transfer behaviors are investigated for both arc-only and hybrid flat-top laser modes. Transient CFD models are developed to simulate the energy of the laser and arc using the surface heat source and double-ellipsoid body heat source models, respectively, and validated through experimentation. The results show that the high-temperature metal fluid flows outward from the center of the molten pool and then backward in the front part. The flat-top laser does not alter the flow field pattern but allows for the spread of more hot liquid metal towards the lateral edges. Furthermore, it is discovered that the flat-top laser reduces the contact angle and promotes a stable molten pool temperature.

The Impact of Sensory Stimuli on Healthcare Workers and Outcomes in Trauma Rooms: A Focus Group Study.

This study investigated issues related to noise, lighting, and temperature in trauma rooms that impact patient care and staff performance. Uncontrolled sensory stimuli can hinder healthcare delivery quality in trauma rooms. High noise and temperature levels can increase staff stress and discomfort as well as patient discomfort. Conversely, proper lighting can decrease staff stress levels and reduce burnout. Sensory overload in trauma rooms is a crucial concern, but no studies have been conducted on this issue. Using a convenience sampling method, 65 trauma team members (e.g., surgeons, physicians, nurses) from six Level I trauma centers in the United States were recruited to participate in 20 focus groups. Focus groups were semi-structured and 1 hr long. Staff covered issues related to communications and disruption from noise sources (e.g., equipment, conversations). Having control over lighting allows staff to change light intensity and facilitate their work during the resuscitation. A well-maintained temperature can provide patient comfort or reduce risk of hypothermia, given that patients can lose body heat rapidly due to loss of blood. Excessive sensory stimuli can result in disrupted communication, fatigue, and stress, making staff susceptible to errors. Staffs' control over environmental conditions may lead to a more efficient, comfortable, and safer environment. Technology should be reliable and flexible to facilitate this.