In scorching Madrid, an advisory from City Hall calls on everyone to drink at least 3 litres of water a day, avoid hot food and stay away from alcohol.
France has activated its national heatwave emergency plan and Paris mayor Anne Hidalgo has ordered staff to check on the elderly and set up "cool rooms" in town halls.
Closer to home, Malaysia's meteorological authorities are awaiting the green light from the government to begin cloud seeding as the hot and dry season depletes reservoirs such as those in Johor.
In Indonesia, some haze-shrouded regencies in Sumatra's Riau province are on standby for water- bombing runs as the dry spell aids the spread of forest fires.
A blistering heatwave - which is said to occur when temperatures rise higher than expected for five consecutive days or more - has sent the mercury shooting up across the globe in recent weeks. India and Pakistan have just experienced it, while Western Europe and parts of North America are now in the grips of one.
As Singapore sweats it out in 34 deg C heat, the mercury is expected to climb to 44 deg C in Spain's ancient Cordoba region, prompting the authorities there to post a red alert, signifying that weather will pose an "extreme risk" to health.
Of the 50 provinces in Spain, 43 are on orange alert, the second- highest warning on a four-colour hazard scale adopted by most European meteorological services. In the city of Seville, people waded into city fountains and others jumped into the Guadalquivir river to beat the heat, which hit 42 deg C.
This week in Paris, the mercury is expected to rise to 37 deg C even as most parts of France remain on orange alert.
Officials, perhaps reminded of the 2003 heatwave, have asked that pedestrians be allowed to seek some respite in air-conditioned public spaces like cinemas and shopping malls. The 2003 heatwave that swept across Europe caused more than 70,000 deaths. In France alone, more than 14,000 people died.
Maximum temperature in Singapore yesterday.
Expected high in the Spanish city of Cordoba this week.
Expected temperature in Paris this week.
Forecast for London this week.
Temperature in Karachi last week, the hottest since 1981.
Recorded in the Indian state of Telangana in May.
"I don't think this heatwave will have the same consequences as the one in 2003 because we weren't as prepared at that time," said Ecology Minister Segolene Royal.
If it hits 36 deg C in London this week, as some have projected, it would be the hottest recorded at the Wimbledon tennis championships, which began on Monday.
The US west coast states of Oregon, Washington and Idaho have also been baking in record-high temperatures and massive wildfires have broken out in recent weeks.
In drought-hit southern California, CNN reported families snapping up cash incentives of US$6,000 (S$8,090) to replace their grass lawns, which account for at least 50 per cent of residents' water usage, with cactus.
Global warming is said to be a factor in the increased incidence of heatwaves in recent years. More extreme weather could be on the cards in the next few months if El Nino sets in. This natural, but disruptive, weather pattern is associated with prolonged droughts in Asia and floods in South America. Many parts of South and South-east Asia are already experiencing dry spells and drought and preparing for a plunge in harvests.
With 22 of its 76 provinces contending with drought, Thailand has asked farmers in the fertile rice-growing Chao Phraya River Basin to delay planting until enough rain sets in this month.
Agricultural problems that could crop up
An El Nino watch is on, stirring up waves of anxiety in the world's rice bowls and bread baskets. There is a high chance that the dreaded weather system - last seen five years ago - will become fully established between now and August. If so, it could cause severe droughts and floods, disrupting harvests and jacking up food prices.
Stocks of rice in key producers and exporters such as India and Thailand are currently abundant, but El Nino is likely to hit padi planting and curb production this year. A price rise could bring fears of inflation and unrest.
El Nino-induced dry weather across the eastern grain belt of Australia - a leading wheat exporter - will hit output, raising the prices of breakfast items such as bread and cereal.
El Nino does not immediately hit palm oil supplies as it takes up to a year for the trees to show the effects of drought. But rising demand from top importers India and China and concerns over an eventual shrinkage in supplies could increase prices.
The two top producers of the Robusta coffee bean, Indonesia and Vietnam, are experiencing drought. Indonesia's output could decline by up to 15 per cent as it is more dependent on rain than Vietnam, which uses irrigation. But Arabica bean production could see a boost as Brazil's coffee belt benefits from warmer weather.
Large global sugar stocks exist for this year, but El Nino could cut next year's sugar cane crop in India, the world's second-largest producer. In 2009, El Nino caused a severe drought that pushed global sugar prices to their highest levels in about 30 years.
Mr Somchit Amnatsan, chief of water management at the Royal Irrigation Department, told The Straits Times: "The situation is very bad compared to the last few years. This May, the rainfall upstream in the north was 55 per cent of the average. In the central region, it is 69 per cent of the average."
In Malaysia, officials have their eyes trained on the skies for cauliflower-shaped towering cumulus clouds so that rain-making operations can begin, the New Straits Times yesterday quoted a Johor official as saying. Two dams that supply to most of Johor Baru and Pasir Gudang industrial areas have breached critical levels .
Indonesia's Riau province is also looking to cloud seeding. Its capital Pekan Baru and some surrounding regencies have been shrouded in an acrid white smoke from forest fires that are common during the dry season or are lit deliberately to clear land for palm oil plantations. Water bombing operations are also being planned as fires continue to burn in Dumai, Pelalawan and other areas.
The worst appears to be over for Karachi, Pakistan's financial capital, where a devastating heatwave took more than 1,000 lives and sent 14,000 to hospital last week. Weeks earlier, more than 2,500 died in a heat wave that hit India.
For some of China's provinces, the coming days spell worry. A heatwave is expected in the southern parts, including Chongqing, Hunan, Jiangxi and Hainan, with soaring temperatures of up to 39 deg C .
In the US, families have been asked to mind the heat while celebrating Independence Day this weekend. In Europe, storms are forecast and will hopefully bring some respite before temperatures start rising again until next week.
•With input from Tan Hui Yee in Bangkok and additional information from Agence France-Presse and Bloomberg