sulphurous

harsh or corrosive in tone

• “an acerbic tone piercing otherwise flowery prose”
• “a barrage of acid comments”
• “her acrid remarks make her many enemies”
• “bitter words”
• “blistering criticism”
• “caustic jokes about political assassination, talk-show hosts and medical ethics”
• “a sulfurous denunciation”
• “a vitriolic critique”

characterized by oppressive heat and humidity

• “the summer was sultry and oppressive”
• “the stifling atmosphere”
• “the sulfurous atmosphere preceding a thunderstorm”