Whether or not a venue is air conditioned can be a key factor when deciding if a night at the theatre is a wise idea on a warm summer's evening.
So WhatsOnStage has put together a run-down of air conditioned West End and Off-West End playhouses that ensure the only thing hotting up this summer is the drama on stage.
This being said, it's important to note that many of the venues not listed here - including larger houses the Palladium, Palace and Theatre Royal, Drury Lane - nevertheless have effective air cooling systems in place, which should ensure a comfortable night in the stalls.
The difference between the air con and air cooling is neatly summed up by Andrew Mills, general manager of the Victoria Palace, St Martin's and the Ambassadors, who told WhatsOnStage:
"An air cooling system takes the air and cools it down (using water) before pumping it back into the auditorium, as opposed to air conditioning which chills the air by using a refrigerant and removing the moisture. Air con is more difficult to install in theatres, generally due to the age of the buildings."
So here (in alphabetical order) is our cool list. Happy, heat-free theatregoing!
This historic Piccadilly venue is one of the oldest air-conditioned playhouses, with a system dating back to a major refurbishment in 1884 (though fear not, it's been updated and serviced a fair few times since).
Current show: The 39 Steps
This ATG-owned Covent Garden powerhouse has a very decent air con system that provides welcome respite from the stifling central London air.
Current show: The Night Alive (until 27 July)
The National is a leader when it comes most things theatre, and that includes air conditioning. The Olivier and Lyttelton both have decent systems (the smaller Cottesloe is currently closed for refurbishment), while the temporary NT Shed has a cooling system facilitated by its four large chimneys.
Daniel Radcliffe fans can rest assured that the theatre that the Harry Potter star currently calls home, on St.Martin's Lane, gets an 'A Star' for air con.
Current show: The Cripple of Inishmaan (until 31 August)
This Delfont Mackintosh venue on Aldwych certainly get the WhatsOnStage seal of air con approval, which will come as a relief to Abba fans everywhere.
Current show: Mamma Mia!
This landmark theatre not only has fine air conditioning but also boasts recently refurbished seating, ensuring a comfortable night on the Cut.
Current show: Sweet Bird of Youth (until 31 August)
Thumbs up too for the air con in the Playhouse, where you can enjoy an Arthurian legend whilst being cooled by 21st century technology.
Current show: Monty Python's Spamalot
Prince of Wales
A Delfont Mackintosh venue, the art deco Prince of Wales is among the smartest in the West End and comes replete with a recently updated air con system - just as well seeing as it hosts one of the hottest tickets in town.
Current show: The Book of Mormon
This ATG-owned theatre, located on the Strand, ensures you can keep as cool as a yellow submarine while watching its current Beatles-themed incumbent.
Current show: Let It Be
Theatre Royal Haymarket
The TRH's air conditioning system may not be the newest in town (installed in 1993) but it'll be sufficient to stop you getting hot and bothered, unlike the protagonist of One Man, Two Guvnors.
Current show: One Man, Two Guvnors
Trafalgar Studios may currently be hosting The Hothouse but the temperatures within this reconfigured space are anything but. The un-air conditioned Studio 2 is currently dark.
Current show: The Hothouse (until 3 August)
This Nimax-owned venue on the Strand stays nice and cool throughout the show, unlike the characters in the WhatsOnStage Award-winning comedy it currently hosts.
Current show: The Ladykillers
This Frank Matcham-designed playhouse has one of the oldest cooling systems in the West End in the shape of a historic 'sliding roof' system - contemporary theatregoers will be pleased to know it retains its cool reputation.
Current show: Billy Elliot - The Musical
The Almeida in Islington has been air conditioned for ten years, ever since Michael Attenborough oversaw refurbishments when he took over as artistic director in 2003.
Current show: Almeida Festival (until 9 August)
The Bush is the only venue on this list not to feature either air conditioning or a cooling system, but the west London venue merits inclusion for providing both fans and ice-cold water for its audiences.
Current show: Josephine & I (until 17 August)
The Finborough, formerly one of the hottest theatres in the capital, installed its air conditioning following an extensive fundraising campaign in 2011.
Dusa, Fish, Stas and Vi (until 3 August)
Menier Chocolate Factory
The Menier in Southwark timed the installation of its recent new air conditioning system perfectly - it was completed on 4 July, just as the mercury began to rise. As the website proudly boasts: "No hot Chocolate here..."
Current show: The Color Purple (until 14 September)
The Dean Street venue not only has one of the coolest blends of comedy, theatre and cabaret in the capital, it also features air conditioning in the main house, downstairs cabaret space and the ever-buzzing bar, and a fan cool unit in the upstairs studio.
Current show: Address Unknown (until 27 July)
St James Theatre
You expect a newly built venue to keep its punters cool and the St James, located on Palace Street in Victoria, doesn't disappoint, with air con in both its main house and studio.
Current show: The American Plan (until 10 August)
The 230-seat Kilburn venue is one of the airiest Off-West End spaces which, coupled with its state-of-the-art air conditioning system, makes it a safe bet on a hot summer's eve.
Current show: The Epic Adventure of Nhamo the Manyika Warrior and His Sexy Wife Chipo (1-17 August)
The Waterloo venue's current show may be set in central Africa but its efficient cooling system should mean you don't feel like you're actually there (except through the transportative power of theatre, of course!).
Current show: A Season in the Congo (until 24 August)
Don't forget, there are a large number of outdoor theatres across the UK offering the most natural air conditioning system available! Click here to see our recent run-down of five of the best outdoor venues
As ever, please make your own suggestions in the comments below