Author's reply to letters on death in heat waves

doi:10.1136/bmj.328.7430.50-a

BMJ 2004;328:50 (3 January), doi:10.1136/bmj.328.7430.50-a

Letter

Author's reply to letters on death in heat waves

The first 150 words of the full text of this article appear below.

EDITOR—Although air movement alone will not always preventheat stroke in air close to body temperature if the air is saturated¹or if sweating is impaired—for example, by drugs withanticholinergic actions²—air movement is an essentialcomponent in preventing heat stroke. Recent advice specificallyrelated to heat stress in Britain over the next decade includednot only a fan but moistening of clothing, open windows, lightclothing, and avoidance of physical exertion.³

Moistening clothing substitutes for sweat. In moving air thisallows evaporative cooling even of people with impaired sweatingand in air warmer than body core temperature. In British (andmost other) heat waves outdoor air is well short of saturation.Relative humidity was 22% near Faversham when the record temperatureof 38.5 °C was recorded there last summer.

Air conditioning can virtually eliminate heat related mortalityeven in a subtropical climate.⁴ However, its capital cost . . . [Full text of this article]

William R Keatinge, professor emeritus

Medical Sciences Building, Barts and the London School of Medicine, Queen Mary and Westfield College, London E1 2AD w.r.keatinge@qmul.ac.uk