Safety and health risks for workers exposed to cold thermal environments: A frozen food processing industry perspective

BACKGROUND: Environmental temperatures in the fresh food industry vary from 0°C to 10°C, and go below -20°C for the frozen food industry, representing risk for the health and safety of workers involved. OBJECTIVE: The aim of this work was to evaluate the cold thermal stress risks for workers working in a frozen food industry. METHODS: A total of 27 acclimatized workers (13 male and 14 female) participated in a study which was conducted during 11 working days. The thermal sensation questionnaire and the cold work health questionnaire (CWHQ) were applied to all participants. Additionally, 4 workers were chosen to be fully monitored with a thermometer telemetry capsule for measuring the intra-abdominal temperature and 8 skin temperature sensors. RESULTS: The lowest recorded hand temperature was 14.09°C, lowest forehead 18.55°C, mean skin temperature had variations of 1.10 to 3.20°C along the working period. Highest and most frequent fluctuations were found in the hand and forehead skin temperatures, small changes were found in mean skin temperature. CONCLUSIONS: Answers to the CWHQ increase concern on clinical forms of “a frigore”, and in two cases the mean body temperature decreased below 35.0°C, which is defined in the current literature as a mild form of hypothermia.

Sex Disparities in Thermoregulatory and Metabolic Responses to Mild Cold Exposure Largely Explained by Differences in Body Mass and Body Surface Area

Sex-related differences in thermoregulatory responses to cold exposure, such as differences in metabolic heat production and fuel selection, are often attributed to differences in morphology and body composition. Whether these differences persist in response to cold when comparing lean, healthy men and women with equivalent total body mass (BM, heat producing capacity) and body surface areas (BSA, heat loss capacity) remains unknown. In this study, we aimed to compare thermoregulatory and metabolic responses to cold exposure in both men and women, before and after matching for BM (± 0.6 kg) and BSA (± 0.01 m2). Data included in this study were derived from four previously published studies and an additional 13 men and 23 women who recently completed an identical 3h mild cold exposure protocol. Included in the analyses were 45 healthy men and 23 healthy women [27 years (95% CI: 25 to 28) in men vs. 34 years (95% CI: 30 to 38) in women, P = 0.0003], including 7 men and women of the same age [28 years (95% CI: 22 to 34) vs. 29 years (95% CI: 22 to 37), P = 0.78] matched for BM and BSA. Using a combination of indirect calorimetry, electromyography and positron emission tomography with 11C-acetate and 18F-fluorodeoxyglucose, we quantified mean skin temperature, whole-body energy expenditure (EE), shivering intensity, brown adipose tissue (BAT) oxidative metabolism and glucose uptake. The cold-induced decrease in mean skin temperature was greater in women than men [-6.4°C (95% CI: -6.7 to -6.0) vs. -5.4°C (95% CI: -5.8 to -5.1), P = 0.0004], whereas EE was higher in men compared to women both during room temperature and cold exposure, with the cold-induced increase in EE being slightly greater in men than women [3.8 kJ·min-1 (95% CI: 3.2 to 4.5) vs. 2.8 kJ·min-1 (95% CI: 2.0 to 3.7), P = 0.07]. In contrast, shivering intensity (%MVC) was higher in women compared to men [3.0 %MVC (95% CI: 2.1 to 3.8) vs.1.8 %MVC (95% CI: 1.5 to 2.2), P = 0.0069]. Cold exposure also increased BAT oxidative index to a similar magnitude in men and women, increasing ~4-fold in men and ~3-fold in women (effect of sex, P = 0.2067). Both fractional glucose uptake [0.022 min-1 (95%CI: 0.017 to 0.027) in men and 0.021 min-1 (95%CI: 0.013 to 0.030) in women, P = 0.02] and net glucose uptake in BAT [92 nmol.g-1.min-1 (95%CI: 69 to 115) in men and 91 nmol.g-1.min-1 (95%CI: 53 to 129) in women] were not different between the sexes without or with matching for BM and BSA. The sex differences in mean skin temperature, energy expenditure and shivering intensity were all lost once participants were matched for BM and BSA. The present results suggest that much of the sexual dimorphism in thermoregulatory and metabolic responses to mild cold exposure can be explained by differences in BM and BSA.

Improved 2000-m Rowing Performance in a Cool Environment With an External Heating Garment

Purpose: Rowers can be in marshaling areas for up to 20 to 25 min before the start of a race, which likely negates any benefits of an active warm-up, especially in cold environments. It is unknown if using a heated jacket following a standardized rowing warm-up can improve 2000-m rowing performance. Methods: On 2 separate occasions, 10 trained male rowers completed a standardized rowing warm-up, followed by 25 min of passive rest before a 2000-m rowing time trial on a rowing ergometer. Throughout the passive rest, the participants wore either a standardized tracksuit top (CON) or an externally heated jacket (HEAT). The trials, presented in a randomized crossover fashion, were performed in a controlled environment (temperature 8°C, humidity 50%). Rowing time-trial performance, core body temperature, and mean skin temperature, along with perceptual variables, were measured. Results: During the 25-min period, core body temperature increased in HEAT and decreased in CON (Δ0.54°C [0.74°C] vs −0.93°C [1.14°C]; P = .02). Additionally, mean skin temperature (30.22°C [1.03°C] vs 28.86°C [1.07°C]) was higher in HEAT versus CON (P < .01). In line with the physiological data, the perceptual data confirmed that participants were more comfortable in HEAT versus CON, and subsequently, rowing performance was improved in HEAT compared with CON (433.1 [12.7] s vs 437.9 [14.4] s, P < .01). Conclusion: The data demonstrate that an upper-body external heating garment worn following a warm-up can improve rowing performance in a cool environment.

Thermal imaging in total knee replacement and its relation with inflammation markers

<abstract> <p>Total knee replacement is an end-stage surgical treatment of osteoarthritis patients to improve their quality of life. The study presents a thermal imaging-based approach to assess the recovery of operated-knees. The study focuses on the potential of thermal imaging for total knee replacement and its relation with clinical inflammatory markers. A total of 20 patients with bilateral knee replacement were included for thermal imaging and serology, where data was acquired on pre-operative day and five post-operative days. To quantify the inflammation, the temperature-based parameters (like mean differential temperature, relative percentage of raised temperature) were evaluated from thermal images, while the clinically proven inflammation markers were obtained from blood samples for clinical validation. Initially, the knee region was segmented by applying the automatic method, subsequently, the mean skin temperature was calculated and investigated for a statistical relevant relationship with inflammatory markers. After surgery, the mean skin temperature was first increased (&gt;2.15 ℃ for different views) then settled to pre-operative level by 90th day. Consequently, the mean differential temperature showed a strong correlation with erythrocyte sedimentation rate (r &gt; 0.893) and C-reactive protein (r &gt; 0.955). Also, the visual profile and relative percentage of raised temperature showed promising results in quantifying the temperature changes both qualitatively and quantitatively. This study provides an automatic and non-invasive way of screening the patients for raised levels of skin temperature, which can be a sign of inflammation. Hence, the proposed temperature-based technique can help the clinicians for visual assessment of post-operative recovery of patients.</p> </abstract>