Poison ivy itches more at night because your body's natural cortisol levels drop after dark, bedding raises skin temperature, and fewer distractions make the sensation harder to ignore. Cool compresses, calamine lotion, and antihistamines can help you find relief and rest more comfortably. The same rash that felt manageable during a busy afternoon can feel unbearable the moment you lie down. Knowing why this happens and what to do about it can make a ...