Why do so many heating pads stop working after a year?

Short lifespan is the single most consistent complaint across Buy-It-For-Life and chronic-pain threads we read, regardless of brand. Reviewers repeatedly report pads that quit or stop reaching full heat within 1–2 years, and several note that auto-shutoff timers and stay-on functions are common failure points. Buyers who use a pad daily should prioritize models with multi-year warranties.