The number and some characteristics of the colds experienced by office workers in London and Newcastle upon Tyne are described.

Age was the only factor found to be strongly associated with the number of colds experienced by an individual. Female staff suffered only 10–15% more colds than male staff. The presence of children in the household had little or no effect. The daily use of public transport also appears to be unrelated to the number of colds suffered.

We are grateful to the Ministry of Pensions and National Insurance for affording us the facilities necessary for the carrying out of this investigation, and particularly to the staffs of the offices who collaborated with us in providing the records and to the members of the Establishment Department and to the staff representatives for their help in the organization of the study. We are also indebted to the Medical Department of the Ministry for their interest and advice. We also wish to record our gratitude to the Shell Petroleum Company, its officers and staff, and particularly the chief medical officer, for their assistance and collaboration, to the management and staffs of the two other London offices studied and to the nurses, Mrs E. Hodgson, Miss M. Petts, Miss L. Waddell and Mrs E. A. Wilson, who collected the records.