Reagents are essential for laboratory and medical testing. Reagent materials are used to detect the presence or absence of a substance, or to test if a specific reaction occurs. Thermal control is vital to preserve reagent materials, which can degrade over time when stored at improper temperatures. When they are kept at room temperature, reagents may become contaminated by microbial growth, which affects test integrity. Reagents can also be negatively affected at low temperatures if they undergo multiple freeze-thaw cycles.