This applied across the many different types of climate - whether in cooler northern US states or in the southern states where temperatures are typically much higher.

　　这适用于许多不同类型的气候 - 无论是在美国北部较冷的州还是在温度通常较高的南部州。

　　The study, Heat and Learning, suggested that hotter weather made it harder to study in lessons in school and to concentrate on homework out of school.

　　这项研究《热和学习》表明，炎热的天气使在校学习变得更困难，并放学后专注于家庭作业也更难。

　　Researchers calculated that for every 0.55C increase in average temperature over the year, there was a 1% fall in learning.

　　研究人员计算，全年平均气温每增加0.55C，学习就会下降1%。

　　Colder days did not seem to damage achievement - but the negative impact began to be measurable as temperatures rose above 21C.

　　较冷的日子似乎没有损害成绩 - 但随着气温升至21摄氏度以上，负面影响开始显现。

　　The reduction in learning accelerated once temperatures rose above 32C and even more so above 38C.

　　一旦气温升至32℃以上，甚至超过38℃，学习减弱的速度就会加快。

　　The study also found the impact of the heat was much greater on low income families and students from ethnic minorities.

　　该研究还发现，暑热对低收入家庭和少数民族学生的影响要大得多。

　　There were suggestions that wealthier families and schools in disadvantaged areas were more likely to intervene if pupils were slipping behind and to find ways to compensate, such as extra tuition.

　　有人认为，如果学生成绩落后，受影响地区的富裕家庭和学校更有可能进行干预弥补，比如通过加课。

　　But it says a "simpler explanation" might be greater access to air conditioning in more affluent families and the schools their children attend.

　　但它表示，“更简单的解释”可能是更富裕的家庭和他们的孩子上的学校更容易获得空调。

　　Joshua Goodman, associate professor at the Harvard Kennedy School of Government, and his co-authors provide evidence that the "heat’s disruption of instruction or homework time is responsible for the observed drop in test scores".

　　哈佛大学肯尼迪政府学院副教授约书亚-古德曼及其合着者提供的证据表明，“高温对教学或作业时间的破坏是导致测试分数下降的原因”。

　　He says students were incrementally more likely to be "distracted, agitated and find it harder to focus".

　　他说学生越来越容易“分心，激动，并且更难以集中注意力”。

　　But Mr Goodman says it would have been harder to carry out similar studies in the education systems in the UK, because the differences in weather conditions would have been much narrower.

　　但古德曼先生说，在英国的教育体系中进行类似的研究会比较困难，因为天气条件的差异会更窄。

　　The wide range of weather conditions in the US allows comparisons within the same year group as well as with test performances in previous years.

　　美国的各种天气条件允许在同一年内进行比较，以及和前几年的测试表现比较。

　　Mr Goodman says the findings also raise bigger questions about whether climate change and global warming will have implications for school achievement.

　　古德曼先生说，调查结果还提出了更大的问题，关于气候变化和全球变暖是否会对学校成绩产生影响。

　　The study also asks whether heat plays a part in the huge regional differences in achievement within the US.

　　该研究还探讨了天气热是否影响了美国境内巨大的区域成绩差异。

　　Northern states such as Massachusetts have very high levels of achievement in international tests, such as the OECD’s Pisa tests, which compare teenagers’ ability in reading, maths and science.

　　像马萨诸塞州这样的北部州在国际测试方面有很高的成就，比如经济合作与发展组织的比萨测试，比较青少年的阅读，数学和科学能力。

　　But southern states such as Alabama and Mississippi are at a level below European countries and closer to Turkey and Mexico.

　　但是，阿拉巴马州和密西西比州等南方州的水平低于欧洲国家，接近土耳其和墨西哥。

　　The researchers also argue there are implications for the ethnic achievement gaps - with black and Hispanic students more concentrated in hotter states of the US.

　　研究人员还认为，这会对族裔成就差距产生影响 - 黑人和西班牙裔学生更集中在美国较热的州。

　　"We argue that heat effects account for up to 13% of the US racial achievement gap," says the study, because of where black and Hispanic students live and because their test scores seem to be disproportionately disrupted by the changes in temperature.

　　“我们认为，热效应占美国种族成就差距的13%，”该研究表示，因为黑人和西班牙裔学生的生活在那里，他们的测试成绩似乎被温度变化不成比例地打乱了。

　　Mr Goodman says the researchers also want to examine the long-term consequences of a hot year on a cohort of students.

　　古德曼先生说，研究人员还想研究炎热的一年对一批学生的长期后果。

　　If students happen to take important exams in a heatwave year, does that mean they are more likely to miss out on exam results and university places?

　　如果学生在热浪年份碰巧参加了重要考试，这是否意味着他们更有可能在考试成绩和大学学位方面表现不佳?

　　Mr Goodman says that policymakers and parents have under-estimated the significance of temperatures in schools and overheated classrooms.

　　古德曼先生说，决策者和家长低估了学校温度和教室过热的重要影响。

　　"Teachers and students already know it’s a problem - because they’ve had to live it," he said.

　　“老师和学生已经知道这是一个问题 - 因为他们必须面对它，”他说。