The critical current of a short YBa2Cu3O7 − δ (YBCO) coated conductor sample degrades in an unprotected quench performed in a nearly adiabatic environment at 30 K. The conductor has Cu stabilizers on both surfaces. The quench is initiated by a heater attached to the sample surface. The amplitude of the transport current is fixed as 91% of the sample's initial critical current. The duration of the current is increased to simulate an unprotected quench and to reach increasing and controlled voltage and temperature levels. A peak temperature of 490 ± 50 K and a heating rate of 1800 K s − 1 are measured when the critical current degrades by ~ 5%. The applied thermal strain on the YBCO layer from 30 to 490 K is estimated to be 0.31% and is applied at a strain rate of ~ 1% s − 1. The rate of temperature change and the time to reach a certain peak temperature, determined by the current density in the Cu stabilizer, are estimated assuming adiabatic conditions based on the short sample case. For a Cu stabilizer current density ranging from 1000 to 2000 A mm − 2, achieved in commercial conductors currently available, the quench detection and protection requires a response time < 200 ms to limit the peak temperature below 200 K. A Cu stabilizer current density higher than 3000 A mm − 2 may challenge the existing detection and protection techniques for the same 200 K limit. Integrating the substrate as part of the stabilizer may help reduce the stabilizer current density to gain more time for quench detection and protection while maintaining the engineering current density.