Moderate Thermal Strain in Healthcare Workers Wearing Personal Protective Equipment During Treatment and Care Activities in the Context of the 2014 Ebola Virus Disease Outbreak

Abstract

The extent of thermal strain while wearing personal protective equipment (PPE) during care activities for Ebola virus disease patients has not yet been characterized. From January to March 2015, 25 French healthcare workers (HCWs) in Conakry, Guinea, volunteered to be monitored while wearing PPE using an ingestible thermal sensor. The mean (standard deviation) working ambient temperature and relative humidity were 29.6 °C (2.0 °C) and 65.4% (10.3%), respectively; the mean time wearing PPE was 65.7 (13.5) minutes; and the mean core body temperature increased by 0.46 °C (0.20 °C). Four HCWs reached or exceeded a mean core body temperature of ≥ 38.5 °C. HCWs wearing PPE for approximately 1 hour exhibited moderate but safe thermal strain.

Physiological Evaluation of Personal Protective Ensembles Recommended for Use in West Africa

“…As seen in the weight-loss data, 60 minutes of low-intensity exercise could result in a person losing 0.94 to 1.48 kg of sweat (about 1.3% to 2.2% of body weight lost). Even though 2 recent field studies 17,18 reported slightly lower weight loss (average, 0.6 kg/h and 0.84 kg/h) than our data in HCWs caring for Ebola patients in Conakry, Guinea, and Kerry Town, Sierra Leone, the environmental conditions differed from our laboratory study. One of the studies found that the weight loss was dependent on the time of the day, being significantly higher from 11:00 AM to 14:59 PM than the rest of the day.…”

Occupational Exposures to Ebola Virus in Ebola Treatment Center, Conakry, Guinea

“…No demographic, professional, or incidental factors were associated with a higher frequency of risk exposure. Obtaining a blood sample was a high-risk activity because this can be a stressful procedure and because of constraints associated with PPE, such as an increased core body temperature ( 15 ).…”

Exercise in personal protective equipment in a hot, humid environment does not affect risk propensity

“…Notably, these environmental conditions simulate the hot-humid conditions encountered in West African Ebola Treatment Units. 8 In the first experimental trial (independent of whether it was the Control or Cooling Trial), the treadmill speed was adjusted within the first 5 min of exercise to elicit 50 ± 4% of age predicted maximum heart rate (e.g., 220-age). This treadmill speed (2.6 ± 0.3 km/h) was maintained constant throughout the remainder of the trial and kept the same during the subsequent trial.…”

“…Thus, healthcare workers wearing PPE, together with the subsequent development of heat stress, may undertake behaviors that compromise the health and safety of both the worker and their patients. 8 One such behavior impacting workplace safety is the tendency to undertake risky behaviors. 23 However, interactions between PPE and heat stress on risk propensity is unknown.…”

“…The purpose of this study was to test the hypothesis that 60 min exposure to heat stress while wearing encapsulating PPE, similar to the conditions and practices in West African Ebola Treatment Units, 8 increases the propensity to take risks compared to a condition in which the magnitude of heat stress will be attenuated via personal cooling under the PPE.…”