Heart rates and energy costs of female tea-leaf pluckers in India were studied while at rest, during walking (with and without basket loads) and during plucking. Walking with loaded baskets was the most strenuous job. The 'fast' category of pluckers had higher, cardiac and gross energy costs than the 'slow' category. When the energy costs were linked to productivity, the 'fast' pluckers had lower costs per unit of productivity. The thermal load was found to be high, and the effectiveness of protective equipment such as indigenous hats has been discussed.