A girl stands surrounded by the jets of a fountain on the South Bank on a hot summer day in central London, July 15, 2013. REUTERS/Andrew Winning (BRITAIN - Tags: SOCIETY ENVIRONMENT) 

R.J. Hernandez, 8, from El Campo, Texas, is buried in sand as he cools off near the Pacific ocean during a heat wave in Santa Monica, California, June 28, 2013. The mercury is predicted to soar well past 110 degrees Fahrenheit and perhaps top 120F (40s and 50s degrees Celsius) starting on Friday in the deserts of southeast California and southern Arizona, Weather.com and the National Weather Service said. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY ENVIRONMENT) 

Isaiah Gonzalez (L) and Isaiah Ceballos sit under a waterfall at Tempe Beach Park as the temperature climbs to 116 degrees Fahrenheit (46.7 degrees Celsius) in Tempe, Arizona June 28, 2013. An "atmospheric blast furnace" engulfed the sunbaked U.S. West in dangerous triple-digit temperatures on Friday, forecasters said, raising concerns for homeless people and others unable to escape near record temperatures expected over the weekend. REUTERS/Joshua Lott (UNITED STATES - Tags: ENVIRONMENT SOCIETY) 

A woman covers herself with a large hat in Times Square during a heat wave in Manhattan, New York, July 19, 2013.
Temperatures in New York City, the biggest metropolitan area in the United States, are expected to reach 99 degrees Fahrenheit (37 C) Friday and 94 F on Saturday before thunderstorms later Saturday break the heat wave, according to weather forecaster AccuWeather.com. REUTERS/Zoran Milich (UNITED STATES - Tags: SOCIETY ENVIRONMENT) 

Two men drift on floats along the Potomac River in Harpers Ferry, West Virginia July 19, 2013. The mid-atlantic region is experiencing a heat wave with temperatures expected to top 100 degrees Fahrenheit (38 degrees Celsius). REUTERS/Kevin Lamarque (UNITED STATES - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

Two girls cool off as they dance beside a fountain at the Sculpture Garden in Washington July 17, 2013. The nation's capital is experiencing a heat wave, with temperatures approaching 100 degrees Fahrenheit (38 degrees Celsius). REUTERS/Kevin Lamarque (UNITED STATES - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

A boy swings across a stream during hot weather in Anstey, central England, July 17, 2013. REUTERS/Darren Staples (BRITAIN - Tags: ENVIRONMENT SOCIETY) 

Men lounge in an inflatable dinghy near a gentrified warehouse on Regent's Canal on a hot summer day in London July 7, 2013. Britain's Met Office weather forecasters have predicted temperatures of up to 29 degrees Celsius (84 Fahrenheit) in Britain's capital, the hottest day of the year so far. REUTERS/Chris Helgren (BRITAIN - Tags: ENVIRONMENT) 

A couple relax in the hot sunny weather as deer pass in Richmond Park in southwest London July 13, 2013. The Met Office said on its website that the hot and sunny weather is due to continue throughout the weekend, with Saturday being the hottest day of the year. REUTERS/Luke MacGregor (BRITAIN - Tags: ENVIRONMENT SOCIETY) 

Crowds fill the beach near Brighton Pier during the hot, sunny weather in Brighton Southern England July 7, 2013. REUTERS/Luke MacGregor (BRITAIN - Tags: ENVIRONMENT SOCIETY) 

A man sunbathes under a t-shirt on Brighton beach, Southern England July 19, 2013. Britain's first prolonged heatwave in seven years has taken the country by surprise, with rails buckling, shops selling out of electric fans, and scientists estimating the surge in temperature could have caused hundreds of premature deaths. REUTERS/Luke MacGregor (BRITAIN - Tags: ENVIRONMENT SOCIETY TRAVEL) 

A couple sunbathe near Bournemouth beach, in Bournemouth, southern England July 14, 2013. REUTERS/Kieran Doherty (BRITAIN - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

A young man uses a water-slide on a sunny summer day at Berlin's Wannsee lido July 26, 2013. Temperatures in Germany are expected to rise up to 38 degrees Celsius (100 degrees Fahrenheit) on Sunday, German Hydrometeorological Institute reported. REUTERS/Fabrizio Bensch (GERMANY - Tags: ENVIRONMENT SOCIETY) 

A woman and her dog cool off at a fountain in a park during a heat wave in central Prague July 27, 2013. Temperatures in the Czech Republic are expected to rise up over 40 degrees Celsius (104 degrees Fahrenheit) on Sunday, Czech Hydrometeorological Institute reported. REUTERS/David W Cerny (CZECH REPUBLIC - Tags: ANIMALS SOCIETY ENVIRONMENT TPX IMAGES OF THE DAY) 

A man jumps in a fountain of the Trocadero Square in front of the Eiffel Tower as hot summer temperatures continue in Paris July 22, 2013. REUTERS/Benoit Tessier (FRANCE - Tags: TRAVEL ENVIRONMENT SOCIETY) 

Caitlin, an Australian tourist, enjoys the sun on a beach of the Croisette during a hot summer day in Cannes July 31, 2013. REUTERS/Eric Gaillard (FRANCE - Tags: TRAVEL SOCIETY TPX IMAGES OF THE DAY) 

Children play under a shower in a public garden to cool off in the summer heat in Nice August 18, 2012. The French local authorities have warned of a heat wave during the weekend. REUTERS/Eric Gaillard (FRANCE - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

A man jumps from a 10 metre (32ft) high public diving platform into Lake Zurich during a sunny summer day in Zurich July 25, 2013. In the background is seen St. Peter church. REUTERS/Arnd Wiegmann (SWITZERLAND - Tags: ENVIRONMENT CITYSPACE TPX IMAGES OF THE DAY SOCIETY) 

Simon Smit and his 5-year old Australian Shepherd dog Geddon jump from a wall into the Limmat river during hot summer weather in Zurich July 27, 2013. REUTERS/Arnd Wiegmann (SWITZERLAND - Tags: ANIMALS ENVIRONMENT SOCIETY) 

People standing on the Quaibruecke bridge watch a man jumping from a 10 metre (32ft) high public diving platform into Lake Zurich during a sunny summer day in Zurich July 25, 2013. REUTERS/Arnd Wiegmann (SWITZERLAND - Tags: ENVIRONMENT CITYSPACE SOCIETY) 

A woman swims in the sea during a hot summer day at Ostia beach, 16 km (10 miles) south of Rome, July 26, 2013. A strong heatwave coming from Africa and nicknamed "Charon" by local forecasters is running over Italy with temperatures rising up to 40 degrees Celsius (104 degrees Fahrenheit). REUTERS/Max Rossi (ITALY - Tags: ENVIRONMENT SOCIETY) 

A couple swims in the sea during a hot summer's day at Ostia beach, 10 miles (16 km) south of Rome, July 26, 2013. A strong heatwave coming from Africa and nicknamed "Charon" by local forecasters is running over Italy with temperatures rising up to 40 degrees Celsius (104 degrees Fahrenheit). REUTERS/Max Rossi (ITALY - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

People enjoy a hot summer day at a public swimming pool in Vienna July 27, 2013. Temperatures in Austria's capital Vienna reached up to 36 degrees Celsius (97 Fahrenheit) on Saturday but Austria's Central Institute for Meteorology and Geodynamics predicts even higher temperatures in the next few days. REUTERS/Leonhard Foeger (AUSTRIA - Tags: ENVIRONMENT) 

A person slides down a huge water pipe at a public swimming pool on a hot sunny day in Vienna July 29, 2013. Temperatures in Austria's capital Vienna reached nearly 36 degrees Celsius (97 Fahrenheit) on Monday, but Austria's Central Institute for Meteorology and Geodynamics predicts a possible record temperature of 39 degrees Celsius (102 Fahrenheit) in the next days. REUTERS/Leonhard Foeger (AUSTRIA - Tags: ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) 

A boy jumps from a 10 meter high platform into a swimming pool during a hot summer day in Hall in Tirol July 23, 2013. REUTERS/Dominic Ebenbichler (AUSTRIA - Tags: ENVIRONMENT) 

Youths shower as others play at a beach a few miles southwest of Athens July 30, 2013. Temperatures around the Greek capital reached 39 degrees Celsius (102.2 Fahrenheit) in one of the hottest days of this summer in Greece, reported local media. REUTERS/Yorgos Karahalis (GREECE - Tags: SOCIETY ENVIRONMENT) 

A man takes a bath while lying on a broken water pipeline on a hot day in New Delhi July 9, 2013. REUTERS/Adnan Abidi (INDIA - Tags: SOCIETY ENVIRONMENT) 

A boy participates in a water fight at People Square in Shanghai July 21, 2013. The temperature in Shanghai rose to 36 degrees Celsius (97 degrees Fahrenheit) on Sunday, reported local news. REUTERS/Carlos Barria (CHINA - Tags: SOCIETY ENVIRONMENT TPX IMAGES OF THE DAY)