The sun produces heat from nuclear reactions deep inside it. All life on Earth depends on this heat.
Credit: NASA/SDO

This summer, the entire globe experienced a heat wave. Western states in America experienced a record-breaking heat wave in late August and early September of 2022.

A heat wave is a period over which the temperature rises well above normal for a particular region. Heat waves may be less dramatic than such natural disasters as hurricanes, earthquakes, or tornadoes, and heat waves tend to cause less damage to property. However, heat waves rank among the deadliest extreme weather.

The varying nature of local climate makes it difficult to establish a simple definition of a heat wave. The temperatures of a heat wave must be hot relative to the average temperatures at a place during a particular time of year. For example, a temperature of 90 °F (32 °C) during the summer is not out of the ordinary for the northern African country of Sudan. However, it would be an exceptionally high temperature for the northern U.S. state of Alaska. Meteorologists agree that high temperatures must persist for more than one full day to be considered a heat wave.

This chart can be used to determine the heat index (HI), a number that describes how people are affected by the combination of temperature and relative humidity. As the temperature and relative humidity rise, the heat index increases. The higher the index, the greater the likelihood that people will develop heat-related illnesses. The risk of illness is low when the index is below 80 °F.
Credit: World Book chart by Linda Kinnaman

Heat waves are sometimes accompanied by high relative humidity. Relative humidity is the amount of water vapor in the air compared with the amount the air can hold at saturation. High relative humidity interferes with the human body’s ability to cool itself through the evaporation of sweat. Thus, high humidity can make a heat wave more uncomfortable and dangerous. Some weather agencies make use of a measure called the heat index, which factors in relative humidity to give a measure of how hot the air feels.

Heat waves are generally created by areas of high air pressure. Meteorologists call these areas highs or anticyclones. Warm highs bring high temperatures and air that contains little moisture. These highs are large weather systems that may affect a region for an extended time. In the summer, a warm high sometimes stalls over North America, for example, causing a heat wave.

The high temperatures of a heat wave can cause dehydration and hyperthermia in people and in animals. Dehydration is a condition in which the body loses too much water. In severe cases, dehydration can lead to a fast heartbeat, low blood pressure, shock, and death. Hyperthermia is a condition that occurs when the body becomes overheated. Forms of hyperthermia include heat exhaustion, heat cramps, and heatstroke (also called sunstroke). Heatstroke is a serious condition that can cause permanent neurological damage and death.

Elderly people, infants, and people with long-term illnesses may suffer heatstroke more readily than others during a heat wave. Hyperthermia can be particularly dangerous for people with long-term medical conditions. Such conditions as asthma, diabetes, heart failure, and high blood pressure place the body’s organs under stress. The added stress from hyperthermia can induce heart attack, breathing failure, and other fatal medical events among such people.

The complexity of diagnosing heat-related deaths has made it difficult for experts to track the toll of heat waves. The World Health Organization estimated that heat waves killed more than 166,000 people between 1998 and 2017. Another study found that approximately 500,000 heat-related deaths occurred worldwide between 2000 and 2019. Despite the uncertainties, experts agree that heat waves are deadly. In 2003, for example, Europe suffered a catastrophic heat wave in which some 70,000 people died.

Heat waves can also put stress on electric power and water services. People’s use of air conditioning strains the electrical grid. Power plants may need more water for cooling. People may also use more water to try to keep cool. When demand for electricity exceeds generating capacity, officials may have to reduce voltage to prevent a blackout. Such a reduction, called a brownout, may damage electrical equipment or cause the equipment to operate less efficiently. High temperatures also buckle pavement and warp railroad tracks.

Drought kills crops. Two farmers examine a Kansas corn field that has been affected by a drought in 2012. Climate scientists suspect such droughts might become more common in some areas due to the effects of global warming.
Credit: © Mashid Mohadjerin, The New York Times/Redux Pictures

Heat waves are dangerous to plants and animals as well. Excessive temperatures can kill animals that cannot find ways to keep cool. Prolonged heat can wither plants. Droughts usually accompany heat waves, compounding the danger to living things. Heat waves and droughts dry out the ground and plants, increasing the likelihood and severity of wildfires.

A Russian firefighter sprays water on a wildfire in the Ryazan region, southeast of Moscow. In 2010, a devastating wave of wildfires wept across Russia following a record-setting heat wave.
Credit: AP Photo

Data suggest that heat waves are increasing in duration, frequency, and intensity. The time of year in which heat waves occur is also expanding. Most climatologists think that climate change brought about by human-caused global warming is driving these changes.

People must exercise caution during heat waves to avoid health problems. Experts advise wearing light-colored, loose-fitting clothing when outdoors and avoiding going out during the hottest part of the day. People should drink fluids regularly but avoid beverages with alcohol or caffeine, which can contribute to dehydration.

People who are homeless or who live in homes without air conditioning are particularly vulnerable to heat waves. During a heat wave, local governments may open air-conditioned cooling centers where people can stay to cool down.

People can help to protect their community during a heat wave. They can air condition their homes only to what temperature is necessary, conserving power. People might be asked to limit water use at certain times to prevent drops in their community’s water pressure. They may be asked to conserve water if the heat wave is accompanied by a drought. Because heat waves increase the risk of wildfires, people may be prohibited from starting fires outdoors.

January 10, 2020

Today, January 10, is the third and final day of the Consumer Electronics Show (CES), the largest digital technology exhibition in the world. CES takes place every year in Las Vegas, Nevada, drawing thousands of tech companies large and small from all corners of the world. Such tech giants as Amazon, Google, and Samsung exhibit their latest products alongside those of small tech manufacturers, developers, and suppliers hoping to grow or get noticed. More than 4,400 companies are represented at this year’s CES, including 21 different companies whose names begin with smart, from Smart Adserver USA to SmartyPans, Inc.

Robots stroll the floor of the Haier booth at the Consumer Electronics Show in Las Vegas on Jan. 6, 2018. Haier is an electronics company based in Qingdao, China. Credit: © Kobby Dagan, Shutterstock

CES is owned and produced by the Consumer Technology Association, the standards and trade organization that represents the massive U.S. consumer technology industry. This year, CES sprawls over 11 official venues covering nearly 3 million square feet (280,000 square meters). About 170,000 tech professionals attend CES each year (including more than 60,000 people from outside the United States) to display and market, but also to attend conferences and see and play with the latest tech gadgets. Attendees need maps to navigate the venue groups—Tech East, Tech West, and Tech South—and patience to wade through the throngs of people distracted by massive video boards, robots, and a host of other electronic bells and whistles.

A woman plays an Xbox One video game console in 2013. Microsoft unveiled the first Xbox console at the January 2001 CES. Credit: © Xbox

The first CES took place in New York City in June 1967. It proved popular and grew quickly along with the consumer technology industry. From 1978 to 1994, CES had two shows per year—a winter exhibition in Las Vegas and a summer show in Chicago. CES has concentrated on just one major Las Vegas event per year since 1998. Numerous consumer electronics have made their debuts at CES, including videocassette recorders (VCR’s) and laser discs in the 1970′s; camcorders and compact discs (CD’s) in the 1980′s; and interactive and satellite technologies, digital versatile discs (DVD’s), high definition television (HDTV), and satellite radio in the 1990′s. Since the early 2000′s, Microsoft Xbox, plasma televisions, blu-ray DVD’s, HD radio, tablets, notebooks, Android devices, smart appliances, driverless cars, 3D printers, wearable technologies, and varying levels of virtual reality have all been seen for the first time at CES. This year’s CES features more than 200 new products as well as innovations in artificial intelligence, cloud services, cyber security, digital health services, drones, mobile payments, and 5G wireless technology.

October 2, 2017

Last night, on October 1, in Las Vegas, Nevada, a gunman killed at least 58 people at an open-air concert near the Mandalay Bay Resort and Casino. The gunman fired from the window of his hotel room on the 32nd floor of the Mandalay Bay, shooting into a crowd of 22,000 people attending a music festival across the street. Armed with numerous automatic weapons, the gunman poured hundreds of bullets into the crowd until police reached his hotel room. The gunman then committed suicide. The attack—which has also resulted in over 500 injuries—is the deadliest mass shooting in United States history. The death toll from the domestic terror attack will most likely rise.

People run for cover as a gunman fires into a crowd attending the Route 91 Harvest country music festival in Las Vegas, Nevada, on Oct. 1, 2017. Fifty-eight people died in the domestic terror attack. Credit: © David Becker, Getty Images

The attack began just after 10 p.m. local time, not long after country music star Jason Aldean had taken the stage at the Route 91 Harvest music festival, a three-day event held in an open-air venue across the Las Vegas Strip from the Mandalay Bay. The Las Vegas Strip, a portion of Las Vegas Boulevard, is famous for its large resort hotels and casinos. Many people in the concert crowd did not react immediately to the attack, as the popping of gunshots was confused with the sound of firecrackers and drowned out by the music being played on stage.

People soon realized the horror of what was taking place, however, and began running for cover and searching for loved ones in the chaos. The shooting paused occasionally as the gunman reloaded his automatic weapons, but the rapid fire then resumed as bullets ricocheted around the concrete concert ground and inflicted further injuries. Police responding to the attack saw gun flashes coming from the Mandalay Bay, and soon zeroed in on the gunman’s locked hotel room. As police used explosives to burst into the room, the gunman shot and killed himself.

Thus far, the shooter, identified as 64-year-old Stephen Paddock, has not been tied with any militant or terrorist groups, and his motive remains unclear. Paddock lived in Mesquite, a small city northeast of Las Vegas. His dead body was found with 23 guns, many of which are readily available in Nevada, a state with some of the least stringent gun laws in the United States. Police found another 19 guns at Paddock’s home in Mesquite.

The previous worst U.S. mass shooting occurred just last year, in June 2016, when a gunman killed 49 people at a gay nightclub in Orlando, Florida. That shooter, who was killed by police, had professed his allegiance to an Islamic terrorist group.