Diverse organisms utilize thermoreceptors to detect and respond to noxious thermal stimuli, however the basic cellular and molecular mechanisms underlying noxious cold perception are not well understood. We developed novel global and local behavioral assays for genetic and cellular dissection of noxious cold responses in Drosophila. Larvae respond to near-freezing temperatures via a mutually exclusive set of singular behaviors– in particular full body contraction (CT). Class III (CIII) multidendritic (md) sensory neurons are specifically activated by cold and optogenetic activation of these neurons elicits cold-evoked behavior. Moreover, blocking synaptic transmission in CIII neurons inhibits CT behavior. Genetically, the transient receptor potential (TRP) channels Trpm, NompC, and Polycystic kidney disease 2 (Pkd2) are expressed in CIII neurons where each is required for CT behavior. We further demonstrate that these TRP channels are not generally required in the propagation of a cold signal, but rather likely play important roles in the initial cold sensing. In support of this, we show that overexpression of Pkd2 in normally cold-insensitive class IV md neurons confers cold sensitivity measured by in vivo cold evoked calcium responses. Thus CIII neurons are multimodal with roles in noxious cold detection and gentle touch mechanosensation. To clarify how these cell may distinguish between cold and gentle touch, we developed and implemented an optogenetic dose response assay revealing that gentle touch mediated head withdrawal behavior responses are due to low threshold activation of CIII neurons, whereas noxious cold evoked CT responses are due to high threshold CIII activation. To investigate how diverse nociceptive thermosensory stimuli are processed, we optogenetically co-activated CIII (cold) and CIV (heat) md sensory neurons. Interestingly, these studies revealed a dominant CT behavioral response with simultaneous activation of CIII and CIV neurons. Moreover, expression of the warm-activated TRPA1 channel in CIII neurons confers heat sensitivity, however, heat-mediated activation of these neurons leads to a majority of larvae exhibiting CT behavior and a dramatic declination in typical heat-induced rolling behavior. To initiate an investigation into cold nociceptive neural circuitry, we have conducted live, in vivo imaging of cold-evoked calcium responses throughout the larval ventral nerve cord (VNC) via GCaMP6 and CaMPARI imaging. These analyses reveal that noxious cold stimuli are transmitted down CIII axons and progress from a posterior-to-anterior direction within the VNC. Collectively, we demonstrate that Drosophila larvae utilize distinct cells and channels to respond to noxious cold temperatures via complex thermosensory and nociceptive circuits.