Alton Towers has apologised after it took up to an hour to evacuate passengers from a broken-down monorail train, as temperatures hit 36.7C (98F) in the UK.
Around 80 people were provided with refreshments after the train stopped due to a "technical issue" at 5.25pm yesterday, the Staffordshire theme park said.
A second train further along the track was then shut down by an automatic system.
Meanwhile, reports that guests had also been stuck upside down on the popular Air ride were dismissed by the park as inaccurate.
The spokeswoman said: "Guests are more focused on any minor delay or technical stoppage at the current time, but any delays that we are experiencing now are within our expected level and will be dealt with according to our stringent processes.
"Alton Towers puts the health and safety of its guests at the forefront of everything it does, which means that from time to time rides will be closed to allow for technical issues to be reviewed."
The latest incident happened four weeks after a carriage on the Smiler ride crashed into a empty carriage, seriously injuring five people, including two who have since undergone leg amputations.