The room was stiflingly hot.

屋里热得人喘不上气来。

《牛津词典》

It was stiflingly hot inside the bus, which reeked of petrol.

公共汽车里面闷热得很，充满汽油味。

youdao

July and August are unpleasantly hot, and Romans traditionally desert the stiflingly hot city in August, with many businesses closing; try to avoid visiting at this time.

七月和八月非常的炎热，八月份的罗马变成令人窒息的沙漠，许多企业甚至会关闭，所以应该尽量避免在这个时候来访。

youdao

"I remember that day very well, " Dr Rosana - as she is fondly known in the hospital - told me in a stiflingly hot ward.

BBC: Latin America & Caribbean

During the first two years that the dome was under construction, Lanier and his father lived in an unheated canvas Army tent that was stiflingly hot in summer and frigid in winter.

NEWYORKER: The Visionary