Ectothermic organisms rely on their surrounding conditions to maintain temperatures within a range that optimizes essential activities such as running, foraging and reproducing. Beyond this range, their performance or fitness decreases with a particularly fast loss of performance at high temperatures.
Climate data are increasingly accessible and are being used to predict which species are most vulnerable to climate change. The available datasets often consist of monthly measurements or predictions for locations every dozens or hundreds of kilometres. Can such coarse data provide realistic vulnerability assessments for small organisms?