HERO is the world’s first forced-air propane heater. Ideal for heavy-duty purposes such as heating a room during construction and renovation, the portable heater features a built-in battery and charging system that delivers up to 35,000 BTUs of heat for eight hours on a single charge. It’s also 50 percent quieter than other portable units. Cost: $190.Mr. Heater. 800-251-0001.www.mrheaterhero.com.