Patrick Olivelle's early upanishads purports to be for the 'ordinary reader with little or no access to the original Sanskrit. Present. Still on page 326 he offers us :
He had this desire: "Let me multiply myself. Let me produce offspring." So he heated himself up. When he had heated himself up, he emitted this whole world, everything that is here. (Tai.Up. II.vi.1)
This 'heating' no doubt refers to 'tapas'.
'Doing Tapas' is a synonym for yogic meditation possibly referring to the bodily heat that is felt by yogis during intense meditation. Lamas for their Finals have to dip in an icy pool and wrap a soaked blanket around them. Drying out the blanket by the use of 'tumo' or yogic heat is a pass. It also has reference to the heat produced by brooding to induce hatching of an egg. Brahman is in short doing meditation.
Swami Gambhirananda in his translation comes closer to something that the 'ordinary reader' as distinct from 'the intelligent general reader' could follow. (I want to thank above all my mother and father without whom I would not be here today). Swami translates this passage as:
He (the Self) wished, "Let me be many, let me be born. He undertook a deliberation. Having deliberated, he created all this that exists.
In Sankara's commentary he distinguishes between 'tapah' as knowledge and 'tapah' as austerity(tapas/meditation) "The idea is that the Self (Brahman) reflected on the plan etc. of the creation of the world."
Being literal can be amusing when it's not misleading. van Buitenen in his Gita translation has Krishna bid Arjuna 'stand up enemy-burner'. I think of Kurukshetra as a video game with death rays deployed from vimanas.