High Reynolds number flows display a wide range of scales, and, depending on the flow, the small scales can be of submicron size. Such small motions can also give rise, at a fixed point, to high frequency signals. To measure turbulence with good fidelity, therefore, we need instrumentation with very good spatial and temporal resolution. Here, we describe a suite of nanoscale sensors capable of measuring velocity and temperature with spatial and temporal resolutions that are at least one order of magnitude higher than that experienced using typical hot wire probes. These probes have led to new insights into high Reynolds number flows, and a number of examples of such insights will be given, including pipe flows, boundary layers, and isotropic turbulence.