Query: “The Lancet researchers found that about 0.5%—half a percent—of all deaths are associated with heat, not only from acute problems like heat stroke, but also increased mortality from cardiac events and dehydration.

Relevant passages:
Hyperthermia <=SEP=> Hyperthermia is elevated body temperature due to failed thermoregulation that occurs when a body produces or absorbs more heat than it dissipates . Extreme temperature elevation then becomes a medical emergency requiring immediate treatment to prevent disability or death .   The most common causes include heat stroke and adverse reactions to drugs . The former is an acute temperature elevation caused by exposure to excessive heat , or combination of heat and humidity , that overwhelms the heat-regulating mechanisms . The latter is a relatively rare side effect of many drugs , particularly those that affect the central nervous system . Malignant hyperthermia is a rare complication of some types of general anesthesia .   Hyperthermia differs from fever in that the body 's temperature set point remains unchanged . The opposite is hypothermia , which occurs when the temperature drops below that required to maintain normal metabolism . The term is from Greek ὑπέρ , hyper , meaning `` above '' or `` over '' , and θέρμος , thermos , meaning `` heat '' .

Heat stroke <=SEP=> Heat stroke , also known as sun stroke , is a severe heat illness , defined as hyperthermia with a body temperature greater than 40.6 C because of environmental heat exposure with lack of thermoregulation . This is distinct from a fever , where there is a physiological increase in the temperature set point of the body . The term `` stroke '' in `` heat stroke '' is a misnomer in that it does not involve a blockage or hemorrhage of blood flow to the brain . Preventive measures include drinking plenty of cool liquids and avoiding excessive heat and humidity , especially in unventilated spaces , such as parked cars , that can overheat quickly . Treatment requires rapid physical cooling of the body .

Air pollution <=SEP=> Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earth 's atmosphere . It may cause diseases , allergies or death in humans ; it may also cause harm to other living organisms such as animals and food crops , and may damage the natural or built environment . Human activity and natural processes can both generate air pollution .   Indoor air pollution and poor urban air quality are listed as two of the world 's worst toxic pollution problems in the 2008 Blacksmith Institute World 's Worst Polluted Places report . According to the 2014 WHO report , air pollution in 2012 caused the deaths of around 7 million people worldwide , an estimate roughly matched by the International Energy Agency .

Cancer <=SEP=> Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body . Not all tumors are cancerous ; benign tumors do not spread to other parts of the body . Possible signs and symptoms include a lump , abnormal bleeding , prolonged cough , unexplained weight loss and a change in bowel movements . While these symptoms may indicate cancer , they may have other causes . Over 100 types of cancers affect humans .   Tobacco use is the cause of about 22 % of cancer deaths . Another 10 % is due to obesity , poor diet , lack of physical activity , and excessive drinking of alcohol . Other factors include certain infections , exposure to ionizing radiation and environmental pollutants . In the developing world nearly 20 % of cancers are due to infections such as hepatitis B , hepatitis C and human papillomavirus ( HPV ) . These factors act , at least partly , by changing the genes of a cell . Typically many genetic changes are required before cancer develops . Approximately 5 -- 10 % of cancers are due to inherited genetic defects from a person 's parents . Cancer can be detected by certain signs and symptoms or screening tests . It is then typically further investigated by medical imaging and confirmed by biopsy .   Many cancers can be prevented by not smoking , maintaining a healthy weight , not drinking too much alcohol , eating plenty of vegetables , fruits and whole grains , vaccination against certain infectious diseases , not eating too much processed and red meat , and avoiding too much sunlight exposure . Early detection through screening is useful for cervical and colorectal cancer . The benefits of screening in breast cancer are controversial . Cancer is often treated with some combination of radiation therapy , surgery , chemotherapy , and targeted therapy . Pain and symptom management are an important part of care . Palliative care is particularly important in people with advanced disease . The chance of survival depends on the type of cancer and extent of disease at the start of treatment . In children under 15 at diagnosis the five-year survival rate in the developed world is on average 80 % . For cancer in the United States the average five-year survival rate is 66 % .   In 2015 about 90.5 million people had cancer . About 14.1 million new cases occur a year ( not including skin cancer other than melanoma ) . It caused about 8.8 million deaths ( 15.7 % ) of human deaths . The most common types of cancer in males are lung cancer , prostate cancer , colorectal cancer and stomach cancer . In females , the most common types are breast cancer , colorectal cancer , lung cancer and cervical cancer . If skin cancer other than melanoma were included in total new cancers each year it would account for around 40 % of cases . In children , acute lymphoblastic leukaemia and brain tumors are most common except in Africa where non-Hodgkin lymphoma occurs more often . In 2012 , about 165,000 children under 15 years of age were diagnosed with cancer . The risk of cancer increases significantly with age and many cancers occur more commonly in developed countries . Rates are increasing as more people live to an old age and as lifestyle changes occur in the developing world . The financial costs of cancer were estimated at $ 1.16 trillion US dollars per year as of 2010 .

Myocardial infarction <=SEP=> Myocardial infarction ( MI ) , commonly known as a heart attack , occurs when blood flow stops to a part of the heart causing damage to the heart muscle . The most common symptom is chest pain or discomfort which may travel into the shoulder , arm , back , neck , or jaw . Often it is in the center or left side of the chest and lasts for more than a few minutes . The discomfort may occasionally feel like heartburn . Other symptoms may include shortness of breath , nausea , feeling faint , a cold sweat , or feeling tired . About 30 % of people have atypical symptoms . Women more often have atypical symptoms than men . Among those over 75 years old , about 5 % have had an MI with little or no history of symptoms . An MI may cause heart failure , an irregular heartbeat , cardiogenic shock , or cardiac arrest .   Most MIs occur due to coronary artery disease . Risk factors include high blood pressure , smoking , diabetes , lack of exercise , obesity , high blood cholesterol , poor diet , and excessive alcohol intake , among others . The mechanism of an MI often involves the complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque . MIs are less commonly caused by coronary artery spasms , which may be due to cocaine , significant emotional stress , and extreme cold , among others . A number of tests are useful to help with diagnosis , including electrocardiograms ( ECGs ) , blood tests , and coronary angiography . An ECG , which is a recording of the heart 's electrical activity , may confirm an ST elevation MI ( STEMI ) if a change known as ST elevation is present . Commonly used blood tests include troponin and less often creatine kinase MB .   Treatment of an MI is time critical . Aspirin is an appropriate immediate treatment for a suspected MI . Nitroglycerin or opioids may be used to help with chest pain ; however , they do not improve overall outcomes . Supplemental oxygen should be used in those with low oxygen levels or shortness of breath . In ST elevation MIs treatments which attempt to restore blood flow to the heart are typically recommended and include percutaneous coronary intervention ( PCI ) , where the arteries are pushed open and may be stented , or thrombolysis , where the blockage is removed using medications . People who have a non-ST elevation myocardial infarction ( NSTEMI ) are often managed with the blood thinner heparin , with the additional use of PCI in those at high risk . In people with blockages of multiple coronary arteries and diabetes , coronary artery bypass surgery ( CABG ) may be recommended rather than angioplasty . After an MI , lifestyle modifications , along with long term treatment with aspirin , beta blockers , and statins , are typically recommended .   Worldwide , about 15.9 million myocardial infarctions occurred in 2015 . More than 3 million people had an ST elevation MI and more than 4 million had an NSTEMI . STEMIs occur about twice as often in men as women . About one million people have an MI each year in the United States . In the developed world the risk of death in those who have had an STEMI is about 10 % . Rates of MI for a given age have decreased globally between 1990 and 2010 . In 2011 , AMI was one of the top five most expensive conditions during inpatient hospitalizations in the US , with a cost of about $ 11.5 billion for 612,000 hospital stays .