Time dependent infrared thermographic evaluation of facemasks

Area of Science:

• Environmental Health
• Human Factors Engineering
• Wearable Technology

Background:

• Limited research exists on the long-term thermal effects of different facemasks during both silent and speaking conditions.
• Understanding facemask-induced thermal changes is crucial for user comfort and compliance.

Purpose of the Study:

• To evaluate temperature variations over time while wearing different facemask types.
• To assess the thermal comfort of facemasks under varying verbal output conditions (silent vs. speaking).

Main Methods:

• A two-way within-subject experimental design was employed.
• Infrared thermographic technology captured facial temperature data.
• Subjective questionnaires measured perceived thermal discomfort and other sensations.

Main Results:

• Facemask use elevated facial temperatures compared to no mask use.
• N95 masks resulted in the highest recorded temperatures in the cheek and nose/mouth areas.
• Speaking conditions showed no significant difference in face temperature but increased subjective ratings of humidity, heat, breathing difficulty, and overall discomfort, particularly with N95 masks.

Conclusions:

• Facemask type significantly influences facial temperature distribution and perceived thermal comfort.
• Both mask type and verbalization impact user comfort, highlighting the need for comfortable mask designs.