A number of countries have set all-time record high temps this week. The cause has been a scorching heat dome that has expanded across Europe. The United Nations’ World Health Organization said more than 1,300 excess deaths have occurred in Europe due to the record-breaking heat. Meanwhile, parts of the US are bracing for a heat dome of their own. The highest number of deaths are believed to have occurred in France. Officials warned that numbers likely would rise as specific death data becomes public. So-called “excess deaths” are estimates of additional death totals based on the number of people expected to die over a certain period of time. The highest temp recorded in Europe during the current heat dome is 114.6 degrees Fahrenheit. It was set Friday in southern France. A heat dome occurs when a high pressure system traps warm air near Earth’s surface. The extreme heat has been caused by a number of factors. Human-caused climate change is a main reason. And warming patterns like the current El Niño weather pattern can make the heat worse. The heat is so deadly in Europe because only 20% of buildings there have air conditioning. That's from a World Resources Institute report. A wide swath of the middle and eastern US will also be covered by a heat dome this week. The summer heat comes just as the nation honors Independence Day. A number of major US cities could see their hottest weather of the year, forecasters say. The heat also complicates things for firefighters battling a fast-moving wildfire along the Utah-Colorado border. Three firefighters have died fighting the blaze. Dozens of fires are raging across the US West. In Utah, authorities have cut back on many Fourth of July activities. They worry that fireworks could cause more fires. And they worry about the effects of smoke from the fires. Reflect: How does extreme weather affect the way you think about your everyday plans?