Millions of people across France woke up drenched in sweat on Tuesday after another night of scorching heat, with most of the population exposed to extreme and exceptional temperatures.

Temperatures will remain exceptionally high around the clock as the national weather service, Meteo France, placed 54 departments under a red heat wave alert.

Italy's health ministry declared a red heatwave alert in 15 cities including Milan and Rome on Tuesday and said the number would go up to 16 on Wednesday.

During a red alert -- the highest level -- the ministry advises people to eat light, stay indoors in the hottest parts of the day and sprinkle themselves with cool water.

Mexico, Kenya, Italy and other nations around the world are experiencing one to two more months of heat stress than they were several decades ago, new research published Monday says, and some areas even more so. Regions previously untouched by heat stress are now feeling it, too.

Extreme feels-like temperatures, heat stress days and tropical nights have all become dramatically more frequent, long and severe over the past six decades as the planet's warming intensifies — a result of the burning of fossil fuels coal, oil and gas — according to a new study published in the journal Nature Climate Change on Monday.

France gritted its teeth Monday for a week of record-busting temperatures, sweltering under a grueling heat wave that combines daytime highs above 40 degrees Celsius (104 Fahrenheit) and sleep-robbing sweaty nights.

The national weather service, Meteo France, said that most of the country — the largest in the European Union and second most populated — is entering what is described as a "plateau" of unrelenting heat-wave conditions that isn't forecast to start easing before Friday at the earliest.

Mourners gathered Sunday in Beirut to pay their respects to a much-loved Lebanese conservationist who died after succumbing to wounds sustained in an Israeli strike on her home on the country's southern coast.

Mona Khalil, who spent more than two decades protecting sea turtles along Lebanon's coastline, was critically injured in the strike on her home in the village of Mansouri earlier this month and died of her wounds Friday. She was 76.

Activists and campaign groups on Saturday paid tribute to Lebanese environmentalist Mona Khalil who died from injuries sustained in an Israeli strike in the country's south, where she dedicated her life to turtle conservation for decades.

Tropical Storm Boris formed Monday and was expected to bring heavy rain, flooding and possible mudslides to parts of southern Mexico's Pacific coast, the U.S. National Hurricane Center said.

Boris was located about 85 miles (135 kilometers) southeast of Acapulco and 50 miles (80 kilometers) southwest of Punta Maldonado, according to the Miami-based weather center. The storm had maximum sustained winds of 40 mph (65 kph) and was moving northeast at 2 mph (3 kph).

Firefighters battled a grass fire in Edinburgh and temperature records toppled as a spring heatwave scorched parts of Western Europe, triggering government warnings about risks to life.

London recorded a rare "tropical night," defined as one in which the temperature does not fall below 20 Celsius (68 Fahrenheit), and Britain's Met Office weather service said the temperature in southern England could hit 35 C (95 F) on Tuesday.

Roads and markets have emptied during afternoons and some farmers have switched to nighttime work to avoid scorching temperatures as a heat wave grips large parts of India.

The India Meteorological Department forecast maximum temperatures Thursday of around 45 degrees Celsius (113 Fahrenheit) in the capital, New Delhi, where authorities have opened temporary "cooling zones" to help people cope.

Torrential rain and floods hit parts of China this week, killing at least 12 people and forcing tens of thousands of people to evacuate, state media reported.

State broadcaster CCTV reported on Wednesday five deaths and 11 people missing in Shimen County of Hunan province in central China after rain battered the region. A rescue operation is underway. By Tuesday evening, more than 19,000 had been relocated, Chinese official news agency Xinhua reported.