A study on the thermal tolerance and latitude in ectotherms reveals that thermal tolerance breadth generally increases with latitude, with a greater rate in the Northern Hemisphere. Terrestrial ectotherms show little variation in upper thermal limits, while lower limits decrease with latitude. In contrast, marine species exhibit a consistent poleward decrease in both upper and lower thermal limits. These findings support hypotheses from smaller-scale studies and highlight differences between terrestrial and marine ectotherms, likely due to varying temperature variability. The study used a large dataset and modern statistical methods to account for multiple variables, including habitat, hemisphere, and taxonomic affinity. Results show that thermal tolerance varies with latitude, with marine species showing more consistent decreases in both upper and lower limits. The study also notes that thermal tolerance metrics and acclimation methods can influence results, but overall, the relationship between latitude and thermal tolerance is robust. The findings suggest that marine species may have more stable thermal limits due to less seasonal temperature variation, while terrestrial species show more pronounced latitude-related changes. The study underscores the importance of considering both ecological and physiological factors in understanding how ectotherms respond to climate change.A study on the thermal tolerance and latitude in ectotherms reveals that thermal tolerance breadth generally increases with latitude, with a greater rate in the Northern Hemisphere. Terrestrial ectotherms show little variation in upper thermal limits, while lower limits decrease with latitude. In contrast, marine species exhibit a consistent poleward decrease in both upper and lower thermal limits. These findings support hypotheses from smaller-scale studies and highlight differences between terrestrial and marine ectotherms, likely due to varying temperature variability. The study used a large dataset and modern statistical methods to account for multiple variables, including habitat, hemisphere, and taxonomic affinity. Results show that thermal tolerance varies with latitude, with marine species showing more consistent decreases in both upper and lower limits. The study also notes that thermal tolerance metrics and acclimation methods can influence results, but overall, the relationship between latitude and thermal tolerance is robust. The findings suggest that marine species may have more stable thermal limits due to less seasonal temperature variation, while terrestrial species show more pronounced latitude-related changes. The study underscores the importance of considering both ecological and physiological factors in understanding how ectotherms respond to climate change.