In many countries, wintertime cold weather is linked to ill-health and intense pressure on public health services. This study examines how both long-term climate change and sub-seasonal variability contribute to the temperature extremes that increase pressures on the UK's National Health Service. The impact of temperature on fractional mortality and hospital admissions due to chronic obstructive pulmonary disease are used as metrics of wintertime pressure on the health system. The focus of the study is on days during the year in which the fractional mortality and hospital admissions attributable to cold weather exceed the five-year return period. These days are henceforth called winter pressure days since they likely to lead to significant pressure on the health service to meet demand. On interdecadal and longer timescales, winter pressure days show a robust decline over recent decades with a reduction from a probability of 0.29 in the pre-industrial period to 0.11 for the period 2000–2016. Comparing the risk of winter pressure days in two different climate model simulations of the historical period and a counterfactual ensemble of only natural climate forcings shows that this decline can be clearly attributed to anthropogenic activity. The average Fraction of Attributable risk due to anthropogenic activity for these two climate models for winter pressure days is −0.94. On sub-seasonal timescales, weather drivers of winter pressure days are assessed through analysis of diagnostics of weather regime lifecycles. This analysis shows winter pressure days occur almost exclusively in the Greenland Blocking regime. Although the risk of winter pressure days is likely to continue to decline with current climate trends, there remains a substantial weather driven risk to the UK health system. Preparing for weather events that cause stress on the system should focus on the analysis and prediction of the Greenland Blocking regime on weekly timescales.

在许多国家/地区，冬季寒冷的天气与健康状况不佳以及对公共卫生服务的巨大压力有关。这项研究探讨了长期的气候变化和亚季节变化如何导致极端温度，从而加剧了英国国家卫生局的压力。温度对慢性阻塞性肺疾病引起的死亡率和住院率的影响被用作冬季对卫生系统压力的指标。该研究的重点是一年中因寒冷天气造成的部分死亡率和住院人数超过五年返回期的日子。这些天被称为冬季压力日，因为它们可能会给医疗服务带来巨大压力，以满足需求。在年代际和更长的时间尺度上，冬季压力日数在最近几十年中显示出强劲的下降趋势，从工业化前时期的0.29下降到2000-2016年期间的0.11。在历史时期的两个不同气候模型模拟中比较冬季压力日的风险，以及仅自然气候强迫的反事实合奏表明，这种下降显然可以归因于人为活动。这两种气候模型在冬季压力日的人为活动造成的平均归因风险分数为-0.94。在亚季节时间尺度上，通过分析天气状况生命周期的诊断来评估冬季压力日的天气驱动因素。该分析表明，冬季的压力天几乎只发生在格陵兰阻塞地区。尽管随着当前的气候趋势，冬季压力日的风险可能会继续下降，但英国卫生系统仍存在大量由天气驱动的风险。准备对系统造成压力的天气事件时，应着重在每周时间尺度上对格陵兰封锁制度进行分析和预测。