You're right about the idea, but a few hours is way too short, because of how the Human body tolerance to strong accelerations. Assuming an acceleration of 10

You're right about the idea, but a few hours is way too short, because of how the Human body tolerance to strong accelerations. Assuming an acceleration of 10 m/s^2 (similar to Earth's gravity), it will takes roughly one year to accelerate to a speed close to the speed of light were relativistic effects occurs, and you will need one more year to decelerate.