You need to ferment your beer at about 17 - 22 C. There are numerous options to do that.
Both Heat Mats and Heat Belts will provide heat, but they are not thermostatically controlled so you could end up making your beer too warm.
If you have somewhere in your house that is about 17 - 22 C then you will be fine to start with.
The other options are aquarium heaters which are thermostatically controlled, you can either put these direct in the fermenter or in a water bath which you then stand the fermenter in.
The next common option is to get a fridge and cnvert it to be a fully temp controlled fermenting cupboard. You add a heat source to the fridge and control it with an external thermostat. This allows you to maintain a consistent temperature through summer or winter.
In the winter I could ferment in the house, but in the summer it gets too warm in the house so I need the fridge solution.