Spiny Crevice Lizards overheated

Question
Mature lizards left too long in sun (?) are unresponsive, altho one is still breathing. Have tried rehydrating with H2O. Now trying Reptaid for electrolytes. Must pry mouth open to give fluids. Any suggestions?

Answer
 Using the syringe to dribble a little at a time just inside lips then stroking the neck to try to induce swallowing.  However if both were in the same situation for the same time with no shaded area to hide, and one has already passed, this one may be too far gone even with intervention by a vet.  I would have rushed both to a good reptile vet first thing.