The prototype NINA platform exploits exothermic chemical heating, as used in ''ready-to-eat'' meals and camping hand warmers. Table S1summarizes the prior history of prototype development. Hatano and coworkers recently described a crude heater that was able to perform a qualitative LAMP assay for anthrax using off-the shelf pocket hand warmers and a Styrofoam box. [27] Dominguez et al. used a similar container with an unspecified phase change material to maintain a stable incubation temperature for a commercial interferon gamma release assay at 37C (although the heat source was conventional). [28] While these interesting approaches are compelling in their simplicity, the bulky apparatus displayed slow warm-up (.30 min.); and for LAMP, significant temperature variation within incubation time, and a lack of run-to-run repeatability was observed. To meet the performance goals implied in the ASSURED guidelines, an optimized heating unit should be engineered to eliminate or minimize all sources of variation. When combined with the temperature-moderating characteristics of engineered phase change materials (EPCM), we demonstrate that an engineered exothermal chemical heating unit can produce a consistent constant-temperature incubator for isothermal NA amplification suitable for a variety of isothermal techniques.