Employers are being offered advice on how to keep their staff cool as Scotland swelters in the heatwave.
Prince Charles admitted it was "bloody hot"
Temperatures nudged 30C on Tuesday and are expected to go up over the rest of the week.
As the mercury rises, the Health and Safety Executive is expecting to see an increase in inquiries from staff concerned about the heat in their workplace.
The temperature also got Prince Charles hot under the collar during a visit to engineering firm Weir Group in Glasgow.
He took time out to speak to many of the workers during a half-hour tour of the factory floor.
They included Andy Brownlie, 25, from Larkhall, who said: "He was just talking about the weather and said it was 'bloody hot'.
"I told him I liked the heat and that I'd just been on my holidays."
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An HSE spokesman told BBC News Online Scotland that while there was a minimum workplace temperature there was no maximum laid down by law.
"You could have high temperatures naturally in cast metal, cooking and food processing industries, so you cannot have one temperature fits all," he said.
However, workplace regulations say that there must be a "reasonable temperature" inside buildings during working hours.
The HSE has issued guidance to help employers make hot conditions bearable for staff.
It said hot weather could lead to lapses in concentration or irritability among people working indoors.
The recommended steps include:
- Providing air conditioning or fans
- Providing blinds to shade windows
- Siting workstations away from direct sunlight
- Providing additional facilities such as cold water dispensers
- Allowing breaks to allow employees to get cold drinks or to cool down
- Introducing more flexible hours to avoid exceptionally high temperatures.
Anyone experiencing particular problems during the heatwave can call an HSE inquiry line on 08701 545500.
BBC Scotland meteorologist Heather Reid said Scotland's warm spell was due to last until the weekend.
At Prestwick, temperatures reached 29C (84F) on Tuesday. Aviemore, Ayr and the Orkney Islands enjoyed their fair share of the good weather with temperatures around 26C (79F).
Scotland's record temperature of 32.8C was set in Dumfries in July 1908.
"I think it could get close to that on Thursday, but I think England has a better chance of breaking its 100F record," said Heather.
"The real intense heat will be south of the border."
Scotland last saw temperatures above 31C in 1995, when Glasgow had a reading of 31.2C.
Heather said inland Scotland would experience the warmest weather as a sea breeze would make the coastal fringes slightly cooler.
Temperature extremes by continent:
Africa: 57.8C, El Azizia, Libya, 13 Sep 1922
Antarctica: 15.0C, Vanda Station, Scott Coast 5 Jan 1974
Asia: 53.9C, Tirat Tsvi, Israel, 21 June 1942
Australasia: 53.3C, Cloncurry, Queensland 16 Jan 1889
Europe: 50.0C, Seville, Spain, 4 August 1881
North America: 56.7C, Death Valley, California, 10 July 1913
Oceania (Pacific Rim): 42.2C, Tugnegareo, Philippines, 29 April 1912
South America: 48.9C, Rivadavia, Argentina, 11 Dec 1905
Source: BBC Weather Centre