In an effort to decrease recurrence and progression rates in non-muscle-invasive bladder cancer (NMIBC), transurethral resection of a bladder tumor is followed by intravesical instillations using Mitomycin-C (MMC) and Bacillus Calmette-Guérin (BCG). In spite of these adjuvant treatment modalities, recurrence and progression rates remain high. Because of these limitations of current standard therapy and the shortage of BCG, there is a search for alternative forms of treatment in NMIBC. Intravesical MMC combined with hyperthermia, especially RF-induced QHT being most extensively investigated in the past 20 years, is one of these alternatives for intermediate- and high-risk NMIBC. There are several different techniques and devices to create hyperthermia of the bladder wall raising temperatures up to 40.5-44.0 ℴ C. Hyperthermia can be the result of ultrasound waves, direct thermal conduction, or electromagnetic fields. An overview of hyperthermia systems concerning their technical aspects, treatment outcomes and adverse events (AE's) will be described in this review. In patients failing standard treatment who are not fit or unwilling to undergo surgery, RF-induced QHT should be considered. Besides QHT, there are more forms of treatment currently being investigated in NMIBC like EMDA and neoadjuvant intravesical chemotherapy, these require more clinical trials to determine patient selection and efficiency.