An early heat wave has been bringing high temperatures to the western United States. Scientists are warning that the extreme heat and dry conditions might become normal. Many places in the American West have been reporting drought conditions for many years. Park Williams is an associate professor in geography with the University of California, Los Angeles. He said, “Heat waves are getting worse in the West because the soil is so dry.” Williams said soil in the western half of the country is the driest it has been since 1895. For example, Phoenix, Arizona is having some of the highest temperatures this week. On Wednesday, it reached 46 degrees Celsius. “We could have two, three, four, five of these heat waves before the end of the summer,” Williams said. An extreme heat warning is in effect until at least Sunday. Reports say in Palm Springs, California, the temperature reached 49 degrees Celsius on Tuesday. Weather experts say a high-pressure system spread over the west this week, causing unusually hot days. Officials in California asked people to save electricity for a few hours on Thursday. They asked people to set their air-conditioning systems to 25.5 degrees Celsius or higher and turn off unnecessary lights and electronics. Officials said they do not expect power outages. But that could change if temperatures remain high in the coming days. The San Francisco Bay area has also had higher than normal temperatures. Kathleen Craft works at a shelter in the city of Livermore, California. She said temperatures had reached 37 degrees Celsius but just one woman came to a special cooling center. Craft said she expects more people as temperatures rise.