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Excessive Heat Warning
An excessive heat warning is a notice issued by the National Weather Service of the United States within 12 hours of the heat index reaching one of two criteria levels. In most areas, a warning will be issued if there is a heat index of at least for more than three hours per day for two consecutive days, or if the heat index is greater than for any period of time. Note that local offices, particularly those where excessive heat is less frequent or in areas with deserts or mountainous terrain, often have their own criteria. High values of the heat index are caused by temperatures being significantly above normal and high humidity, and such high levels can pose a threat to human life through conditions such as heat stroke, heat exhaustion, and other heat-related illnesses. Danger to athletes Due to the extreme illnesses that can occur, athletes should limit their physical activity when an excessive-heat warning is issued. According to the National High-School Sports-Related Injury ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Weather Service
The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce, Department of Commerce, and is headquartered in Silver Spring, Maryland, Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970. The NWS performs its primary task through a collection of national and regional centers, and 122 local List of National Weather Service Weather Forecast Offices, Weather Forecast Offices (WFOs). As the NWS is an agency of the U.S. federal government, most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Index
The heat index (HI) is an index that combines air temperature and relative humidity, in shaded areas, to posit a human-perceived equivalent temperature, as how hot it would feel if the humidity were some other value in the shade. The result is also known as the "felt air temperature", "apparent temperature", "real feel" or "feels like". For example, when the temperature is with 70% relative humidity, the heat index is . The humidity where the heat index feels like itself is typically left unstated. The heat index example in this case, 41°C, feels like 41°C only when the humidity is 21%. The human body normally cools itself by perspiration, or sweating. Heat is removed from the body by evaporation of that sweat. However, high relative humidity reduces the evaporation rate. This results in a lower rate of heat removal from the body, hence the sensation of being overheated. This effect is subjective, with different individuals perceiving heat differently for various reasons (such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperatures
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible to extract energy as heat from a body at that temperature. Temperature is important in all fields of natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at , but only 8 g of water per cubic metre of air at . Three primary measurements of humidity are widely employed: absolute, relative, and specific. Ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Stroke
Heat stroke or heatstroke, also known as sun stroke, is a severe heat illness that results in a body temperature greater than , along with red skin, headache, dizziness, and confusion. Sweating is generally present in exertional heatstroke, but not in classic heatstroke. The start of heat stroke can be sudden or gradual. Heatstroke is a life-threatening condition due to the potential for multi-organ dysfunction, with typical complications including seizures, rhabdomyolysis, or kidney failure. Heat stroke occurs because of high external temperatures and/or physical exertion. It usually occurs under preventable prolonged exposure to extreme environmental or exertional heat. However, certain health conditions can increase the risk of heat stroke, and patients, especially children, with certain genetic predispositions are vulnerable to heatstroke under relatively mild conditions. Preventive measures include drinking sufficient fluids and avoiding excessive heat. Treatment is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Exhaustion
Heat exhaustion is a severe form of heat illness. It is a medical emergency. Heat exhaustion is caused by the loss of water and electrolytes through sweating. The United States Department of Labor makes the following recommendation, "Heat illness can be prevented. Remember these three things: water, rest, and shade." Causes Common causes of heat exhaustion include: * Hot, sunny, humid weather * Physical exertion, especially in hot, humid weather * Due to impaired thermoregulation, elderly people and infants can get serious heat illness even at rest, if the weather outside is hot and humid, and they are not getting enough cool air. * Some drugs, such as diuretics, antihistamines, beta-blockers, alcohol, MDMA ('Ecstasy', 'Molly'), and other amphetamines can cause an increase in the risk of heat exhaustion. Especially during physical exertion, risk factors for heat exhaustion include: * Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Antonio, Texas
("Cradle of Freedom") , image_map = , mapsize = 220px , map_caption = Interactive map of San Antonio , subdivision_type = Country , subdivision_name = United States , subdivision_type1= State , subdivision_name1 = Texas , subdivision_type2 = Counties , subdivision_name2 = Bexar, Comal, Medina , established_title = Foundation , established_date = May 1, 1718 , established_title1 = Incorporated , established_date1 = June 5, 1837 , named_for = Saint Anthony of Padua , government_type = Council-Manager , governing_body = San Antonio City Council , leader_title = Mayor , leader_name = Ron Nirenberg ( I) , leader_title2 = City Manager , leader_name2 = Erik Walsh , leader_title3 = City Council , leader_name3 = , unit_pref = Imperial , area_total_sq_mi = 504.64 , area_total_km2 = 1307.00 , area_land_sq_mi = 498.85 , area_land_km2 = 1292.02 , area_water_sq_mi = 5.79 , area_water_km2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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