The inaugural hot yoga class was held in the museum's Tropical Forest in Dunedin last night.
The 50 participants holding yoga poses, across the forest's three levels, included Karitane residents Jude Ritchie (62) and Jan Hellyer (66).
It was the first time the friends had tried hot yoga, let alone among scuttling quail, hairy tarantulas and about 1000 fluttering butterflies.
The temperature in the forest for the one-hour class was about 28degC, with 75% humidity.
''If it all gets too much we'll just lie down and meditate,'' Ms Ritchie joked, before striking her first pose.
Adam Brown (37), of Dunedin, bought tickets for himself and his mother Natalie Brown (62).
Neither had tried yoga and both found the class ''great'', Mr Brown said.
''It wasn't too intense.''
Butterflies sitting on you while holding a pose ''enhanced'' the experience, he said.
He would do another class if it was held in the forest again.
Hot Yoga Dunedin co-owners Donna Wikio and Lili Wyant talked people through poses last night, including the butterfly, caterpillar and the sphinx.
Ms Wikio said he hoped the yoga class in the museum would be the first of many.
Museum public engagement manager Rachel Cooper said demand for tickets to the sold-out class on Thursday was so high the museum would definitely be helping host such classes again.
