T he term polar vortex has become part of the everyday vocabulary after the widespread media coverage of the extreme cold events over the United States during the early winter of 2014. However, there is some confusion in the media, general public, and even within the science community regarding what polar vortices are and how they are related to various weather events. This confusion is illustr...

The dynamical coupling between the stratospheric and tropospheric circulations yields a statistically significant level of potential predictability for extreme cold events throughout much of the Northern Hemisphere (NH) mid–high latitudes on both month-to-month and winter-to-winter timescales. Pronounced weakenings of the NH wintertime stratospheric polar vortex tend to be followed by episodes ...

The purpose of this study was to determine whether day of the week, season, federal holidays, and severe weather conditions affected emergency department (ED) volume in Montgomery County, Ohio. A retrospective analysis of ED visits from July 1, 2010 to July 1, 2011 was conducted. Meteorological data in Montgomery County was obtained from the National Oceanic and Atmospheric Administration (NOAA...

No previous study exists in China examining the impact of extreme temperature on morbidity outcomes. In this study, we investigated the impact of heat waves and cold spells on hospital admission in Shanghai, China. Daily hospital admission data between January 1, 2005 and December 31, 2008 were collected from the Shanghai Health Insurance Bureau. The heat wave was defined as a period of at leas...

The ability of psychrophiles to survive and proliferate at low temperatures implies that they have overcome key barriers inherent to permanently cold environments. These challenges include: reduced enzyme activity; decreased membrane fluidity; altered transport of nutrients and waste products; decreased rates of transcription, translation and cell division; protein cold-denaturation; inappropri...

Two portable battery powered pulse oximeters were tested on Joint Services expeditions to the Sahara Desert and the Andes mountains. Their ability to measure changes in pulse, oxygen saturation of arterial haemoglobin (SaO2), their durability, ease of use, power systems and ancillary equipment were therefore evaluated in two extreme conditions. Although durable, easy to use and with good monito...

Military operations in cold weather naturally pose many problems. One of the most important is related to immobilization of men for long periods of time, preventing them from indulging in even the smallest movements from fear of having their presence detected. The experimental work being reported is concerned with the reactions of soldiers sitting quietly for periods of 2 to 3 hours in environm...

It has been hypothesized that the increase in temperature in this century could lead to an increase in frost damage to plant tissues. Several models have been proposed to describe the development of cold hardiness, but never taking into account extreme climatic and/or physiological events. Our results on walnut tree (Juglans regia L.) show that cold hardiness was best correlated with average da...