The whitefly, Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) is a key agricultural pest and virus vector in diverse crops throughout the world. It is distributed in warm environments with short periods of extreme temperatures, suggesting mechanisms to adapt and expand to new areas. The aim of this study was to determine how temperature affects fitness of B. tabaci, particularly during short periods of stressful high temperatures. Thermotolerance curves were constructed at different one-hour heat shocks (37, 39, 41, 43, 44, 45 °C and a control at 25 °C), measuring its effect on three life history traits involved in fitness: survival, fecundity and viability. Then, temperatures were selected to establish an induced thermotolerance or hardening treatment (40 °C/1h, 25 °C/1h and 45 °C/1h) to compare with the basal thermotolerance (45 °C/1h). The heat shocks significantly affected B. tabaci survival between 41 °C (82.5%) and 45 °C (2.7%). Fecundity was only affected significantly at 45°C without oviposition. Viability diminished significantly at 44 °C (67%). Thermal hardening increased survival from 2.73% (45 °C/1h) to 10% in males and 33% in females; although it was significantly higher in females, only. These results show high thermotolerance of B. tabaci to heat shocks, evidencing plasticity of the species to survive a broad range of temperatures (≥ 25 °C), which contributes to explaining the expansion of biotype B distribution in areas and seasons with extreme high temperatures.