How effective are thermal blinds and how do thermal blinds work will vary a little depending on the type of blind, but in general they work by creating a more effective barrier between the room and the glass of your windows, helping to keep the room temperature stable. Thermal Pleated Blinds trap air in their fabric pockets, whilst Thermal Roller Blinds and Thermal Vertical Blinds reflect energy back to wherever the air is warmest. In all their forms, Thermal Blinds will help to keep your space cooler in summer and warmer in winter, and they'll even help to save you money on your energy bills!