Some will have to heat their FLEX during the long winter months and Spike has the solution. The FLEX heater was carefully engineered to match the heating needs to maintain set temperatures even in the coldest winter garage. Spike uses a built in thermostat which stops the heater from getting too warm. This means you get a gentle warming action when your beer drops below your desired temp (opposed to rapid heating which can overshoot or 'cook' your wort).