A distinguished physiologist, Bill Keatinge was best known for his pioneering research on the effects of cold and heat on human health and on the mechanisms controlling blood vessels.

Cold weather is probably the greatest global cause of ill-health and death, yet it is the most easily countered. People who know that they will face extreme weather conditions in remote places normally learn how to avoid death from a catastrophic loss of body heat. They will, for example, make sure that they build a shelter against the wind if they are at risk of being caught out in a blizzard. Surprisingly, most deaths from cold weather result from relatively mild exposures during everyday life in cities.

In the early 1980s the media shocked society by reporting that in Britain 100,000 elderly people chilled to death in their homes every winter. The conventional wisdom was that they died of hypothermia — severe stress from the cold caused their body temperature to fall so low that their hearts and brains stopped working.

But these deaths were not due to hypothermia. Heart attacks and strokes were the cause of most of the deaths, with respiratory illness being responsible for most of the rest. Keatinge’s research, involving experiments on volunteers, showed that normal adjustment by the body to mild cold was to blame.

“When the body needs to conserve heat,” he wrote, “it shuts down blood flow to the skin, stopping the blood from transferring heat from the body core to the skin. However, that also shifts blood out of the skin.” This could cause the rest of the circulation to be overloaded, and “to correct it, salt and water are removed from the blood by the kidneys and excreted. That deals with the surplus volume, but increases the concentration of substances in the blood that promote clotting.”

Generally this does no harm to younger people with good arteries, but it is dangerous for old people, whose arteries are often in a bad condition. In them, clots are liable to form and block the arteries, causing heart attacks and strokes in winter.

Keatinge discovered that excess winter mortality was greatest in countries with mild winters, such as Britain. The number of deaths depended on how well people kept warm, indoors as well as outdoors. Those expecting severe winters took far greater care to keep warm.

In Britain about a thousand people are killed by hot weather in an average summer, most of them aged 75 or older. In the exceptionally hot summer of 2003 more than 3,000 people died. Global warming may well produce more runs of hotter days and, therefore, more deaths.

Few people travelling in hot deserts or tropical forests die from the heat. They are usually well aware of the need to take enough water and to rest in the shade at the hottest time of the day. As with cold-related deaths, the great majority of the people who die in heat waves are living ordinary lives at home.

Heart attacks and strokes are again the largest causes of death in heat waves. The reason for them is that both water and salt are lost in sweat. This makes the blood more concentrated and more liable to form clots that block arteries supplying the heart and brain.

William (Bill) Richard Keatinge was born in 1931. In 1940 he was evacuated to Canada, returning to the UK after four years. He was then educated at Rugby School after which he studied medicine at Pembroke College, Cambridge, and St Thomas’ Hospital in London. Between 1956 and 1958 he did his national service with the Royal Navy in Cambridge and became director of studies in medicine and Junior Fellow at Pembroke College.

After spending some time in San Francisco as a Fulbright Scholar he returned to England and, in 1961, accepted a Medical Research Council appointment and fellowship at Pembroke College, Oxford.

In 1969 he was appointed Reader in physiology in the Department of Physiology at the London Hospital Medical College (LHMC) and promoted to professor in July 1970. In 1981 he was appointed head of the Department of Physiology.

In 1990 the basic medical sciences departments from LHMC and St Bartholomew’s Hospital Medical College were merged with Queen Mary and Westfield College (QMW), London. Keatinge became Head of Physiology in the joint school.

In 1991 Keatinge was elected Dean of the Faculty of Basic Medical Sciences at QMW. It was a difficult time — student numbers were increasing rapidly but staff appointments were being reduced. His competence as an administrator was greatly appreciated.

He retired in 1995 and was made an emeritus professor. But he continued his active career until a few weeks before his death.

Keatinge collaborated with many scientists from a number of countries and he developed particularly close links with Russia. He was fascinated with the Russian language and learnt to speak it well enough to be understood on his visits to the country.

He was a prolific writer, publishing some 200 papers in academic journals and many chapters in textbooks of both physiology and medicine. He was an enthusiastic teacher of human physiology to undergraduates and postgraduates throughout his career.

Keatinge was very interested in classical archaeology and history, and he enjoyed the outdoors, with a particular interest in forestry.

His first wife Annette, whom he married in 1955, died in 2000. His second wife, Lynette, and the three children of his first marriage survive him.

Professor W. R. (Bill) Keatinge, physiologist, was born on May 18, 1931. He died of prostate cancer on April 11, 2008, aged 76