Climate change is causing widespread river warming and a loss or fragmentation of cold-water habitat for aquatic species such as Atlantic salmon. During periods of thermal stress when water temperatures are high, cold-water fishes seek out cold-water patches known as ‘thermal refuges’ to alleviate thermal stress. These refuges are known to promote resilient and diverse aquatic ecosystems that can withstand both short-term heat waves and potentially long-term climate warming, but they are not distributed uniformly in space. As a result, proactive human alterations of rivers, such as thermal habitat creation or restoration, is an emerging research topic. Two studies were conducted to investigate proof-of-concept thermal habitat creation designs in rivers in Nova Scotia. In the summer of 2022 and 2023, two thermal refuges were created by using engineered hyporheic zones to rapidly cool the warm river water. In summer 2023, we created a thermal refuge using a municipal well and pump to discharge groundwater to the river at a flowrate of 8.89 L/s and temperature of 9ºC, when the river was up to 30ºC. The spatial extent and thermal anomalies were monitored via a drone equipped with a thermal infrared camera and water temperature loggers. A notable thermal plume (≥2ºC colder than ambient river water temperatures) was revealed, measuring approximately 55 meters squared at the water surface. Time-lapse cameras were installed to monitor fish aggregations in both thermal refuge systems. The findings from this study will benefit future projects aiming to proactively maintain thermal diversity in warming rivers.