The past tense of Swelter is sweltered.
verb. ['ˈswɛltɝ'] suffer from intense heat.
1. Verb, non-3rd person singular present Terlingua is a desert region and the temperatures swelter in May and June. 2. Adjective, comparative Think about what will make you swelter unnecessarily. 3. Noun, singular or mass Low-lying towns swelter in summer heat.
verb. ['ˈswɛltɝ'] be uncomfortably hot.