Aiming to open a new design space that connects three areas of architectural, interaction and textile design, the knitted structures Furry lines and Groovy squares were designed. By combining conventional textile yarns together with conductive yarns, the result investigates the sensation of warmth through the design of knitted structures. The purpose is to offer a synesthetic experience that correlate the physical and visual perception of space and focuses on tactility as an asset to create interactive architectural environments. The structures were made using different knitting techniques, combining a silver-coated copper yarn and conventional textile yarns. The silver coated copper yarn is used both for heat generating and touch sensing properties. Connected to a microcontroller able to sense and react on small differences in electricity, the textile becomes a touch sensor itself. By offering feed-back to hand touch DESIGNING WITH HEAT DELIA DUMITRESCU ANNA PERSSON by becoming warmly pleasant to the skin, new types of patterns can be created using the combination between heat and human touch that exceed the visual dimension. Designing with heat exemplifies how visible and invisible expressions merge into one experience, expressed through the textile material. The textile structure is perceived both through the eyes of imagination and the skin as heated patterns. The prototypes show how heat could be part of the surface aesthetics alongside with colour and shape.