Effect of wearing an N95 filtering facepiece respirator on superomedial orbital infrared indirect brain temperature measurements

Abstract

Purpose To determine any effect of wearing a filtering facepiece respirator on brain temperature. Methods Subjects (n=18) wore a filtering facepiece respirator (FFR) for 1h at rest while undergoing infrared thermography measurements of the superomedial periobital region of the eye, a non-invasive indirect method of brain temperature measurements we termed the superomedial orbital infrared indirect brain temperature (SOIIBT) measurement. Temperature of the facial skin covered by the FFR, infrared temperature measurements of the tympanic membrane and superficial temporal artery region were concurrently measured, and subjective impressions of thermal comfort obtained simultaneously. Results The temperature of the skin under the FFR and subjective impressions of thermal discomfort both increased significantly. The mean tympanic membrane temperature did not increase, and the superficial temporal artery region temperature decreased significantly. The SOIIBT values did not change significantly, but subjects who switched from nasal to oronasal breathing during the study (n=5) experienced a slight increase in the SOIIBT measurements. Conclusions Wearing a FFR for 1h at rest does not have a significant effect on brain temperatures, as evaluated by the SOIIBT measurements, but a change in the route of breathing may impact these measurements. These findings suggest that subjective impressions of thermal discomfort from wearing a FFR under the study conditions are more likely the result of local dermal sensations rather than brain warming.

Reusable Face Masks as Alternative for Disposable Medical Masks: Factors that Affect their Wear-Comfort

“…According to Figure 4 , Sample E shows the highest thermal conductivity at 0.0006955 and 0.0012134 W/cm °C, regardless of whether a filter is used. Several cases have suggested that there is a positive correlation between air permeability and thermal conductivity, because the entrapped still air appears to provide significantly more insulation than the fibers and thus retains the heat in the in-mask atmosphere [ 29 , 32 , 33 ]. However, the test results of the masks appear to indicate little correlation between thermal conductivity and air resistance (R 2 = 0.05), which could be because air permeability is not influenced by the material used for masks, whereas this is not true for thermal conductivity.…”

Comparing mask fit and usability of traditional and nanofibre N95 filtering facepiece respirators before and after nursing procedures

“…a Statistically significant at P<0.05, computed by paired Student's t-test. caused by effects on core temperature but may be associated with warming of facial skin covered by the respirator and warming of inspired air [28,29]. Poor communication and speech intelligibility have been shown to be concerns when wearing a respirator, given the potential for miscommunication that leads to critical treatment mistakes [12].…”

Powered air-purifying respirator use in healthcare: Effects on thermal sensations and comfort

“…Research studies addressing physiological responses to N95 filtering facepiece respirators (N95 FFR), at sedentary and low-moderate work rates in temperate ambient environments over 1–2 hr, have reported no significant effects on core (intestinal, rectal) temperatures [1,6] or on indirect measurements of brain temperature. [7] The temperature of the facial skin under an N95 FFR rises above baseline values and regularly reaches the level at which facial heat sensory receptors are activated and transmit afferent impulses to the brain, [7,8] thereby suggesting that this is the site of origination of respiratory protective equipment-associated heat perceptions. Thus, actions that serve to decrease the temperature of facial skin covered by this equipment may decrease thermal sensations and, secondarily, improve comfort and tolerance.…”