A catheter apparatus for intravascular renal neuromodulation, comprising: an elongated shaft (12, 16) extending along an axis, the elongated shaft comprising a proximal end region and a distal end region, the distal end region including a controlled flexure zone (32, 34, 44); at least one thermal element coupled to and/or distal from the controlled flexure zone (32, 34, 44), the at least one thermal element configured to contact an intravascular tissue surface and apply thermal treatment to renal nerves positioned adjacent the intravascular tissue surface; and an active cooling element, wherein the active cooling element further comprises an open circuit cooling element; wherein the controlled flexure zone (32, 34, 44) is configured for controlled flexure about the axis in at least a first direction to position the at least one thermal element into contact with a renal blood vessel proximate to renal nerves, the contact between the at least one thermal element and renal blood vessel creating a tissue interface, wherein the at least one thermal element is configured to apply thermal treatment via the intravascular tissue surface to ablate the renal nerves; and wherein the active cooling element is configured to remove heat from the at least one thermal element at a rate sufficient to avoid unsafe temperatures at the tissue interface during ablation of the renal nerves, characterised in that the active cooling element comprises at least one infusion port in the thermal element, and wherein the thermal element and active cooling element together comprise an irrigated electrode, wherein the irrigated electrode comprises a tip located at the distal end of the distal end region of the elongated shaft (12, 16). an elongated shaft (12, 16) extending along an axis, the elongated shaft comprising a proximal end region and a distal end region, the distal end region including a controlled flexure zone (32, 34, 44); at least one thermal element coupled to and/or distal from the controlled flexure zone (32, 34, 44), the at least one thermal element configured to contact an intravascular tissue surface and apply thermal treatment to renal nerves positioned adjacent the intravascular tissue surface; and an active cooling element, wherein the active cooling element further comprises an open circuit cooling element; wherein the controlled flexure zone (32, 34, 44) is configured for controlled flexure about the axis in at least a first direction to position the at least one thermal element into contact with a renal blood vessel proximate to renal nerves, the contact between the at least one thermal element and renal blood vessel creating a tissue interface, wherein the at least one thermal element is configured to apply thermal treatment via the intravascular tissue surface to ablate the renal nerves; and wherein the active cooling element is configured to remove heat from the at least one thermal element at a rate sufficient to avoid unsafe temperatures at the tissue interface during ablation of the renal nerves, characterised in that the active cooling element comprises at least one infusion port in the thermal element, and wherein the thermal element and active cooling element together comprise an irrigated electrode, wherein the irrigated electrode comprises a tip located at the distal end of the distal end region of the elongated shaft (12, 16).