The user's surroundings also play an important role in the effects of the acid. Usually, the user begins to feel the first effects from the acid 30 minutes after taken. After 90 minutes the trip is in full effect (NIDA). The physical effects of the drug include dilated pupils, muscle tightness, higher body temperature, increases heart rate and blood pressure, sweating, loss of appetite, sleeplessness, dry mouth, and tremors (Kusinitz 45). A person's sensations and feelings change much more dramatically than the physical signs. The user may feel several different moods at once or may swing from one mood to another very rapidly (NIDA). Sensations may seem cross over, giving the user the feeling of hearing colors and seeing sounds. Many users say the drug causes boundaries between the self and other to disappear (Mass 45). These changes can be frightening and can cause extreme panic. Once the trip is over, a person may still feel confused. Many LSD users experience flashbacks of the drug's effect on the body. A flashback can occur suddenly, often without warning, and may occur within a few days or up to a year after LSD use (NIDA). Ecstasy, Special K, acid and other club drugs will continue to be a part of the rave scene, even though they are illegal. The usage may decline, but there will always the dedicated raver who looks forward to rolling, snorting some K, or