Yes it will heat the terrarium. The Heating Pad will heat the glass and the glass will dissipate the heat into the terrarium and warm the tank. It is not my favorite way to heat a terrarium but it is a common way. To put the heating pad on the side you would want to peal the "cover" off the adhesive side and stick it to the tank.


I prefer to use Ceramic Heat emitters. It provides a radiant heat to the tank from above. It can heat the tank Day and night and produces no light. They last much longer than heat bulbs and heat the tank without zapping much of the humidity from it.