In the video Atilla shows that because the ground states cannot gain energy from their environment, they are protected against noise or thermal fluctuations. However, there is a limit to that protection. When do you think this protection does not hold anymore?
Protection starts to fail when thermal energies get close in size to the energy gap. This is a frequent restriction for other solid state systems and it is related to states using the thermal energy to get excited and overcome the energy gap, leaving the ground state.