Tested during the Atacama desert fieldwork in 2019, this project aimed to test the efficiency of slow heat release of materials to warm a shelter during night time. Testing soap stone as one of the most efficient thermal accumulators and slow release of heat, the shelter, clad in mylar, tested diffrent heat release result in the hilly contrasting temperature of the desert. Ranging from 35 degrees during the day and 5 degrees during the night, the soap stone is elevated by a self activating wax piston when the sun rises, and automatically lowered when the temperature drops at sunset.