The Polar Bear Plus GSM™ is a versatile heating and cooling reactor module for flow chemistry applications using glass static mixers/reactor chips (GSMs). To achieve high reproducibility and facilitate scale-up, the control of mixing and temperature is essential, particularly for highly exothermic or fast, mixing-dependent reactions. Compatible with all Uniqsis GSMs from 250µL to 20mL total channel volume, the unit delivers precise flow reactor temperature control from –30°C up to +150°C. The Polar Bear Plus GSM™ will accommodate all sizes of GSM from a single large chip, or using a conductive insert, up to 2 of the smaller GSMs. The Polar Bear Plus GSM reactor is easy to use and is completely self-contained, requiring only an electricity supply for operation—no cardice, refrigerants, or messy heat transfer fluids. An insulated PTFE cover with view window allows GSMs to be removed and refitted without the need to disconnect the fluidic connections.