For a particular reversible reaction at temperature T, ΔH and ΔS were found to be both +ve. If Te is the temperature at equilibrium, the reaction would be spontaneous when:

We know, ΔG = ΔH – TΔS
For a spontaneous reaction, ΔG < 0.
Given that ΔH and ΔS are both positive, for ΔG to be negative, the term TΔS must be greater than ΔH. This means that the temperature T must be high enough.
At equilibrium, ΔG = 0, so ΔH = TₑΔS.
Therefore, the reaction will be spontaneous when T > Tₑ.