She's at her best when 'the heat is on'. [=when she feels a lot of pressure; when she needs to finish something quickly]
She said things in 'the heat of the moment' [=when she was angry for a short period of time] that she later regretted.
The company has 'turned up the heat on' [=has put extra pressure on] its employees to finish the job quickly.
(..) You think you're saving anyone? It's terribly well balanced. Well, if there's too much weight, you lose power on the swing, so. I got it! Create a heat seal. I can... - I can supercharge the spire from below. - Running numbers. - A heat seal could work with enough power. - Thor, I got a plan! (..)2015 Avengers: Age of Ultron
(..) Where is this guy now? (African language) Don't tell me your man swindled you, I sent you six short range heat seekers and got a boat full of rusted parts. Now, you will make it right, or the next missile I send you will come very much faster. Now, minister, where were we? (African language) (..)2015 Avengers: Age of Ultron