Alvaro Barrientos, Associated Press
A woman uses a fan to cool off in the shade on a hot summer day, in Pamplona, northern Spain, Tuesday, June 30, 2015. A mass of hot air moving north from Africa is bringing a heat wave to Europe, with France the next in line for a scorching day. Forecasters said southern France could see temperatures over 40 degrees Celsius on Tuesday, a day after Cordoba in southern Spain recorded 43.7 degrees Celsius (110.66 Fahrenheit).

PARIS — Commuters bared lots of skin, temperatures broke records in cities and towns, and millions gulped down water or splashed away in it as Western Europe sweltered in a heat wave.

Authorities in France and elsewhere, mindful that thousands died during a 2003 heat wave, were reaching out to the elderly, families and other vulnerable people Wednesday to make sure they realized the health risks. Paris officials opened special air-conditioned rooms for the public.

A mass of hot air moving north from Africa has sent temperatures spiking in Spain, Portugal, Britain and France in recent days. Temperatures in Paris were expected to hit 39 degrees Celsius (102 Fahrenheit) Wednesday afternoon.

On Tuesday, southwest France saw temperatures reaching 42 C (107 F) and Cordoba in southern Spain recorded nearly 44 C (111 F).

The last time Paris saw 40 C (104 F) in July was in 1947, according to Meteo France forecaster Francois Gourand. August is hotter, but 2003 was the last time Paris saw such high temperatures in that month.

At Paris' Gare de Lyon train station, public announcements repeatedly reminded people to drink lots of water and not over-exert themselves. Medics were on call in case of emergencies.

"We have a lot of heat-wave days ahead of us," Gourand said, noting that a wide swath of southern France from Toulouse to Lyon was looking at temperatures of up to 41 C (105 F) until the middle of next week.

Climate is on many French minds for another reason. Paris is hosting a major international climate conference in December that will aim to curb heat-trapping greenhouse gas emissions.

In Britain, less accustomed to sweltering climes than its neighbors, one cheeky Web site gave a "taps aff" — Scottish for "tops off" — rating to London, where the mercury was to hit 34 C (93 F) Wednesday.

Many commuters outside the London subway weren't bothered by the sweltering heat. Some responded with a classic British quip: "Mustn't complain."

"I'm loving it. I can't complain," said Maggie Cloud, a university student who planned to relax in the park. "We pay so much money to go abroad to holidays, and now we have the weather here. It's cheaper."

In Spain, tourists looking for sun and beach time didn't mind the heat either.

"Beautiful. We're coping very well," said Petroneo Zaldumbide, a 65-year-old Ecuadorean on holiday.

Spanish authorities said the past week brought record June temperatures, with Madrid recording its highest temperature in 95 years as thermometers came close to 40 C (104 F).

Portugal, which is bracing for a challenging forest fire season after an exceptionally dry winter and spring, had the hottest, driest June for 12 years.

The Civil Protection Service said more than 9,700 firefighters, 2,000 vehicles and 45 aircraft would be on permanent standby this season. Some 230 fire lookout towers across the country will also be staffed by unemployed people.

Sylvia Hui in London, Jorge Sainz in Madrid and Angela Charlton in Paris contributed to this report.