On August 25, 2017, Hurricane Harvey made landfall near Corpus Christi, Texas. The ensuing unprecedented flooding throughout the Texas coastal region affected millions of individuals.1 The statewide response in Texas included the sheltering of thousands of individuals at considerable distances from their homes. The Dallas area established large-scale general population sheltering as the number of evacuees to the area began to amass. Historically, the Dallas area is one familiar with “mega-sheltering,” beginning with the response to Hurricane Katrina in 2005.2 Through continued efforts and development, the Dallas area had been readying a plan for the largest general population shelter in Texas. (Disaster Med Public Health Preparedness. 2019;13:33–37)

Cold cathodes have been fabricated using two different nitride structures as a thin film emitting layer. The A1N and graded AlGaN structures are prepared by metalorganic chemical vapor deposition (MOCVD) on an n-type 6H-SiC substrate. Individual aluminum grids are perforated with an array of either 1, 3, or 5μm holes through which the emitting surface is exposed. After device fabrication, a hydrogen plasma exposure was found to be necessary to activate the cathode. The devices have displayed a limited lifetime and a small percentage of the devices operate, although half of the devices with 5μm holes functioned. The highest measured collector currents are 0.1μA for A1N and l0nA for AlGaN at grid voltages of 110V and 20V, respectively. The grid currents are typically 10 to 104 times the collector currents.