Temperatures reached inside stand-up ultraviolet treatment boxes

Heat generated within ultraviolet treatment units can exacerbate eczema. To document the actual temperature changes within the treatment units, we measured the air temperatures in standard stand-up psoralen plus ultraviolet A (PUVA), narrowband ultraviolet B (UVB), broadband UVB, and combination UVA/UVB cabinets using a thermocouple thermometer. For the latter unit, we also measured the air temperatures with and without ventilation systems, and actual skin temperatures on individuals undergoing light treatment. The air temperatures rose significantly in all the treatment units, more so with PUVA and narrowband UVB boxes, and were highest with the ventilation systems shut off. Skin temperatures also rose significantly, but less dramatically. Ventilation is essential in maintaining comfortable temperatures within ultraviolet treatment units.