Xeroderma Pigmentosum (XP) patients limit outdoor activity to dusk hours or wear full UV protective gear, including a hood with a visor, full clothing and gloves. In particular, commercially available gear has been designed and tested for UV protection only, but it leads to substantial solar heat gains, resulting in human thermal discomfort, de facto restricting outdoor activity to relatively cooler conditions, impacting quality of life.
Here, we present measurements performed in the laboratory and outdoors on UV gear typically used by XP patients and identify some strategies to improve thermal comfort by limiting solar heat gains. Materials characterisation was performed with a UV-Vis-NIR spectrophotometer equipped with a 150 mm integrating sphere, and outdoor measurements were performed with a thermal camera and temperature sensors on manikins.
Improvements are achieved by selecting materials that decrease the transmission in the near-infrared portion of the solar spectrum while retaining total UVR protection and, for the visor, transparency in the visible range. In particular, for the visor, we identified two options, leading to a reduction of the solar transmittance from 0.85 to 0.60, for a clear vision option (visible transmittance 0.76, 0.87 untreated), to 0.36 for a slightly darker option (visible transmittance 0.57), which would be optimal for bright light conditions.
The identified solutions reduce overheating under the UV protective gear and can contribute to improving the quality of life of XP and skin cancer patients, as well as improving both UV and thermal safety for outdoor workers.