These are the data from thermal tolerance trials from putting sea urchin embryos into vials in a thermal gradient. Development was scored after 2, 10 or 20 hours. Tolerances where tested for the upper and lower thermal limit. Upper thermal limit trials are "heatblocks" and lower thermal limits are "coldblocks". The data are formatted for logistic regression analysis, so each vial has two row entries, one with the the number of successes for each category and one with the number of failures for each category.