Cooling vests alleviate perceptual heat strain perceived by COVID-19 nurses

Johannus Q de Korte; Coen C W G Bongers; Milène Catoire; Boris R M Kingma; Thijs M H Eijsvogels

doi:10.1080/23328940.2020.1868386

Cooling vests alleviate perceptual heat strain perceived by COVID-19 nurses

Temperature (Austin). 2021 Jan 20;9(1):103-113. doi: 10.1080/23328940.2020.1868386. eCollection 2022.

Authors

Johannus Q de Korte¹, Coen C W G Bongers¹, Milène Catoire², Boris R M Kingma^{2

3}, Thijs M H Eijsvogels¹

Affiliations

¹ Radboud university medical center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands.
² TNO, the Netherlands Organization for Applied Sciences, Department of Human Performance, Unit Defence, Safety and Security, Soesterberg, The Netherlands.
³ University of Copenhagen, Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, Copenhagen, Denmark.

Abstract

Cooling vests alleviate heat strain. We quantified the perceptual and physiological heat strain and assessed the effects of wearing a 21°C phase change material cooling vest on these measures during work shifts of COVID-19 nurses wearing personal protective equipment (PPE). Seventeen nurses were monitored on two working days, consisting of a control (PPE only) and a cooling vest day (PPE + cooling vest). Sub-PPE air temperature, gastrointestinal temperature (T_gi), and heart rate (HR) were measured continuously. Thermal comfort (2 [1-4] versus 1 [1-2], p_condtition < 0.001) and thermal sensation (5 [4-7] versus 4 [2-7], p_condition < 0.001) improved in the cooling vest versus control condition. Only 18% of nurses reported thermal discomfort and 36% a (slightly) warm thermal sensation in the cooling vest condition versus 81% and 94% in the control condition (OR (95%CI) 0.05 (0.01-0.29) and 0.04 (<0.01-0.35), respectively). Accordingly, perceptual strain index was lower in the cooling vest versus control condition (5.7 ± 1.5 versus 4.3 ± 1.7, p_condition < 0.001, respectively). No differences were observed for the physiological heat strain index T_gi and rating of perceived exertion across conditions. Average HR was slightly lower in the cooling vest versus the control condition (85 ± 12 versus 87 ± 11, p_condition = 0.025). Although the physiological heat strain among nurses using PPE was limited, substantial perceptual heat strain was experienced. A 21°C phase change material cooling vest can successfully alleviate the perceptual heat strain encountered by nurses wearing PPE.

Keywords: COVID-19 pandemic; Thermal comfort; cooling vest; thermal sensation; thermoregulation.

Grants and funding

The work was supported by the TNO Brains4Corona grant (MedicalHeatStress) and the ZonMw VIMP grant under grant number 5460010031. The infographic has been supported by HeatShield under the EU Horizon 2020 program grant [nr. 668786].