When stress, fear or sadness weigh on us, our hearts can suffer — even break. But there are ways to mend our broken hearts. This hour, TED speakers share stories and ideas about soothing heartache. Guests include cardiologist Sandeep Jauhar, law professor Jeannie Suk Gersen, pediatric nurse Hui-wen Sato, and climate activist Knut Ivar Bjørlykhaug.