If you increase the temperature, the rate of production of hydrogen gas will increase.
You can read about the effect of temperature on reaction rates at
Consider the reaction of zinc metal with hydrochloric acid.
If you increase the temperature, the H⁺ ions will hit the surface of the zinc more frequently. The rate of formation of H₂ will increase.
You cannot increase the temperature of just the reactants. You must increase the temperature of the whole reaction mixture.
The H₂ molecules will also be moving more rapidly. The bubbles of H₂ gas will form and leave the surface of the zinc more rapidly. This will make room for more H⁺ ions to attack the surface of the zinc.