The thermal preferences in a grain mass and respiration at various temperatures in mites (Acari: Acarididae) of medical and economical importance [Acarus siro (L. 1758), Dermatophagoides farinae Hughes 1961, Lepidoglyphus destructor (Schrank 1871), and Tyrophagus putrescentiae (Schrank 1781)] were studied under laboratory conditions. Based on the distribution of mites in wheat, Triticum aestivum L., grain along a thermal gradient from 10 to 40°C, L. destructor, D. farinae, and A. siro were classified as eurythermic and T. putrescentiae as stenothermic. The lowest preferred temperature was found for D. farinae (28°C), followed by A. siro (28.5°C), L. destructor (29.5°C), and T. putrescentiae (31.5°C). The relationship between the respiration rate and the temperature was similar for all four mite species. The highest respiration was found in the range from 31 to 33°C This is ≈2°C higher than the preferred temperature of these species. The lower temperature threshold of respiration ranged from 1 to 5°C and the upper threshold ranged from 45 to 48°C Acclimatization of A. siro to temperature regimes of 5, 15, and 35°C resulted in thermal preferences between 9 and 12°C, 9 and 20°C, and 28 and 35°C, respectively. The respiration rate of acclimatized specimens increased with the temperature, reaching a maximum at 29.0°C for mites acclimatized at 5 and 15°C and a maximum at 33.7°C for those acclimatized at 30°C.