In this article, Fiber Bragg Grating (FBG) technology used to implement fiber sensors is explained and some applications in temperature and strain measurements are presented. In the first section, the fundamentals and operation principles of FBGs are shown as well as optical fiber sensing interrogators. The second part of the article presents applications of temperature measurements in power transmission lines, shrinkage measurements in concrete structures, and spatiotemporal measurement variations in variations of temperature between groundwater and surface water (GW-SW).