Climate effects on population stability may manifest through their influence on breeding behaviour. For example, in extreme temperatures individuals may trade off their own body condition and survival against that of their young. Despite convincing evidence that this trade-off (parental care choice; Ghalambor & Martin 2001) exists in nature, this has rarely been investigated with respect to the potential impact of climate change on parental investment strategies. Here, we investigated the extent to which high temperatures affect offspring provisioning rates in a cooperative breeder (the pied babbler, Turdoides bicolor). In this species, individuals steadily lose body mass above a critical maximum temperature of 35.5 ^oC. We investigated the ramifications of this critical temperature point by determining the ability of individuals to maintain provisioning rates to young (a costly activity) during high temperatures. We predicted that on hot days when birds were struggling to thermoregulate (above 35.5 ^oC), they would trade off their own condition against that of their offspring. We found that adults provisioned dependent young significantly less on hot versus cold days. However, neither weight gain nor foraging efficiency differed for adults on these days, supporting theoretical predictions that during periods of environmental stress, adults in longer-lived species will trade off maintenance of their own condition against that of their young.  More detailed analysis revealed that parents significantly reduced their investment on hot days whereas subordinate helpers did not. These differences in investment among adults support previous empirical evidence in fairy-wrens (Russell et al 2007), suggesting that one benefit of group-living for cooperative breeders is that they can reduce investment in their own young when helpers are present to provide additional care. Our findings provide some of the first empirical evidence that hotter temperatures are affecting reproductive investment decisions in cooperative breeders.