Temperature Profiles of Sunlight-Exposed Surfaces in a Desert Climate: Determining the Risk for Pavement Burns.

Plentiful sunlight and high temperatures in desert climates cause burn injuries from contact with sun-exposed surfaces. The peak temperature, times, and surfaces of greatest risk are not well described. This work recorded temperature measurements of six materials in a desert climate. Surface temperatures of asphalt, brick, concrete, sand, porous rock, and galvanized metal were measured throughout the summer, along with ambient temperature, and sunlight intensity. Samples were placed in both shade and direct sunlight for evaluation of sunlight effect. Seventy-five thousand individual measurements were obtained from March to August 2020. Maximum recorded temperatures for sunlight-exposed porous rock were 170°F, asphalt 166°F, brick 152°F, concrete 144°F, metal 144°F, and sand 143°F, measured on August 6, 2020 at 2:10 pm, when ambient temperature was 120°F and solar irradiation 940 W/m2. Sunlight-exposed materials ranged 36 to 56°F higher than shaded materials measured at the same time. The highest daily temperatures were achieved between 2:00 and 4:00 pm due to maximum solar irradiance. Contour plots of surface temperature as a function of both solar irradiation and time of day were created for all materials tested. A computational fluid dynamics model was created to validate the data and serve as a predictive model based upon temperature and sunlight inputs. This information is useful to inform the public of the risks of contact burn due to sunlight-exposed surfaces in a desert climate.

Research: Testing of a Novel Portable Body Temperature Conditioner Using a Thermal Manikin.

A battery-operated active cooling/heating device was developed to maintain thermoregulation of trauma victims in austere environments while awaiting evacuation to a hospital for further treatment. The use of a thermal manikin was adopted for this study in order to simulate load testing and evaluate the performance of this novel portable active cooling/heating device for both continuous (external power source) and battery power. The performance of the portable body temperature conditioner (PBTC) was evaluated through cooling/heating fraction tests to analyze the heat transfer between a thermal manikin and circulating water blanket to show consistent performance while operating under battery power. For the cooling/heating fraction tests, the ambient temperature was set to 15°C ± 1°C (heating) and 30°C ± 1°C (cooling). The PBTC water temperature was set to 37°C for the heating mode tests and 15°C for the cooling mode tests. The results showed consistent performance of the PBTC in terms of cooling/heating capacity while operating under both continuous and battery power. The PBTC functioned as intended and shows promise as a portable warming/cooling device for operation in the field.