In the testing literature, the term load testing is usually defined as the process of exercising the system under test by feeding it the largest tasks it can operate with. Load testing is sometimes called volume testing, or longevity/endurance testing.
Keep your taste buds awake, drink an energy drink. This may raise your level of alertness for a reasonable amount of driving time. Suck or munch on an apple, orange, or even a lemon to keep taste buds awake. The more tangy the food item the better. (Pull over somewhere safe before eating anything that you can't just pop in your mouth, however.
Stay awake for two full days to induce incredible fatigue and then cook dinner, clean the house, walk the dog and see how you feel. Please do not compare MS fatigue to you being tired from only a few hours of sleep - it's not the same at all. Cognitive Function (Brain Fog)