Health surveillance and workplace surveillance are two related but different aspects of occupational health services. The assessment of heat stress using heat indices and thermal models in connection with meteorological data is an important part of surveillance of workplace heat. The assessment of heat exposure provides the basis for occupational health services. Workers should have health surveillance if the high heat stress cannot be reduced.
A number of aspects of human health are caused by, or associated with, local climate conditions, such as heat and cold, rainfall, wind and cloudiness. Any of these aspects of health can also be affected by climate change, and the predicted higher temperatures, changes in rainfall, and more frequent extreme weather conditions will create increased health risks in many workplaces. Important occupational health risks include heat stress effects, injuries due to extreme weather, increased chemical exposures, vector-borne diseases and under-nutrition.