Exploiting the igloo principle and greenhouse effect to regulate humidity and temperature.

BACKGROUND: Toxic epidermal necrolysis can be fatal and nursing care with careful monitoring of temperature and humidity can improve survival rate. We adapted the greenhouse and igloo principle using a common hood to monitor the temperature and humidity. METHODS: A small heater with a regulator was placed in a mini hood and temperature was recorded inside the uncovered hood and hood covered with green cloth and aluminium foil separately. The regular hood was placed over a volunteer and the temperature was measured inside the open hood and hood covered with green cloth and aluminium foil separately. The relative humidity was also monitored using Zeal mercury dry--wet bulb hygrometer. RESULTS: Temperature increase was most marked in the foil-covered hood followed by cloth-covered hood, both with the heater and the volunteer. Similarly, in the volunteer study, the humidity was best maintained inside the aluminium foil-covered hood. CONCLUSION: We recommend the use of regular hood with suitable cover to monitor the humidity and temperature of patients with toxic epidermal necrolysis.

UVA and UVB in sunlight, optimal utilization of UV rays in sunlight for phototherapy.

The disadvantages of sunlight as the source of UVA for phototherapy include variation with time, place, season, and atmospheric conditions. In the present study at Coimbatore, India we measured the UVa and UVB irradiance for one year using PMA 2100 meter. UVB irradiance was maximum between 12.00 noon-1.00 p.m (19.50 microw/cm2 to 40.2 microw/cm2) and UVA between 12 noon-1.15 p.m. (4.70 mw/cm2 tp 6.59 mw/cm2). The ratio of UVA was 1:500 to 1:600 during early hours and late evening and 1:200 during mid-day. At peak time (11.30 a.m. to 1.30 p.m.), the exposure time for 1 June of UVA was 2 min. 32 sec. to 4 min. 31 sec and for 10 mj of UVB it was from 4 min. 55 sec. to 11 min. 22 sec. We recommend the ideal time for UVB phototheraphy between 11.00 a.m. to 2.00 p.m. and for PUVASOL between 9.30 a.m. to 11 a.m. and 2 p.m. to 3.30 p.m. when incidental UVB and infrared rays responsible for heat are less.