Climate change results in crops being exposed to higher temperatures. Understanding how this affects production is key to designing resilient genotypes and adapted practices. Microvine, a mutant of grapevine, is a powerful model because of its small size and continuous fruiting phenotype. This study was thus performed to assess the impact of elevated temperatures on carbon balance using both photosynthesis and respiration measurement as well as growth estimations. One-year old potted Microvines were installed in a growth chamber. A multiplexed, whole plant gas-exchange chamber was designed and used in parallel with single leaf data cuvettes. Temperature steps of 48 hours were applied during the day (20-35°C) and night (15-30°C). Remarkably, neither night, nor day temperature had an effect on day photosynthesis and night respiration respectively. Higher temperature reduced photosynthesis with similar relationships both at the leaf and at the whole plant level, independently of the leaf age. By contrast, elevated temperature increased night respiration but with strong dependency on the leaf age and with lower values when compared to whole plant measurements. The respiration of stem and trunk were likely responsible for these discrepancies. Based on these data plus growth estimates from leaf development rate and leaf dry matter content, a carbon balance model was derived. It showed an average 4.6% and 3.3% reduction of the C balance every 2°C increase during the day and during the night respectively. Our results clearly highlight the deleterious effect of elevated temperature on grapevine C balance with potential negative impact on berry set and sugar accumulation.