A, Temperatures recorded by the patch+EPA (filled symbols) and by an ambient temperature sensor mounted on spectacles (open symbols) when worn by an adult indoors (temperature, 65°−69°F; 6:12–6:42 and 7:05–7:7:32) and outdoors (temperature, 37°F; 6:42–7:05). B, Difference in temperature for the patch+EPA vs the ambient temperature sensor; patch wear time can be easily discerned. C, Temperatures recorded by the patch+EPA (filled symbols) and by an ambient temperature sensor (open symbols) when worn by an adult indoors (temperature, 70°−72°F; 16:00–16:30 and 16:55–17:15) and outdoors (temperature, 87 °F; 16:30–16:55). D. Difference in temperature for the patch+EPA versus the ambient temperature sensor; patch wear time can be easily discerned. Also note that, when not wearing the patch+EPA, both the patch+EPA and the ambient temperature sensor recorded similar temperatures.