swelter

verb

1. (intransitive)To suffer terribly from intense heat.
2. (intransitive)To perspire greatly from heat.
3. (transitive)To cause to faint, to overpower, as with heat.

   “It was so rare a piece of fun To see the swelter'd cattle run”

noun

1. Intense heat.

   “The summer swelter did not relent until late in September, most years.”