The distribution of temperature across a nanoscale electronic conductor is related to many fundamental aspects, such as heat dissipation, the conversion of heat to electricity, and heat-pumping at the nanoscale. However, it is hard to probe temperature and temperature differences at the nanoscale. Consequently, many questions related to the mentioned subjects remained open. We develop local temperature probes to study the distribution of temperature across atomic and molecular conductors with the aim of demonstrating temperature-related nanoscale phenomena and efficient heat-to-electricity conversion at the nanoscale.