When the day heats up, small business owner Chung Kee Wa, 68, changes how he tends his oil palm plantation in Yong Peng, in Malaysia’s southern Johor state.Oil palms younger than three years offer little shade, so he tends them in the early mornings and evenings, spraying pesticide, applying fertiliser or weeding. “We try our best to avoid going to the plantation around noon,” Chung said.He carries extra drinking water and, as a smallholder, decides when to slow down or change his hours.But...