At lower doses, this increase may only be noticed when the body is put into action. Your heart rate may be normal while you're sitting or walking, but as soon as action is taken, like running or playing hacky sack, the heart pounds harder, and in larger doses, faster. Also, larger doses may generate fast heart beat even at rest. Dilated pupils doesn't occur at low doses, except if applied directly to the eyes. There may be giddiness and other deliriant effects like confusion.
Thoughts seem to come faster, sometimes at breakneck speeds.
Delirium generally produces a certain amount of anxiety. Contradistinctively, a profound sense of relaxation is possible at lower doses. Sleepiness usually takes over a few hours into the experience, sometimes so strongly that exhaustion happens. There may be lucid dreaming at this point, or a state of semi-consciousness where sleep and waking interlace. This category includes dilation of pupils, drying of oral and nasal cavities, flushing of skin and increased temperature, and increased heartrate.