By Sean Hill, Eddie Kasner, and Lav Khot
Washington State University’s AgWeatherNet program (AWN) maintains and supports a network of over 225 public and 133 private weather stations throughout Washington State. AWN collects near real-time weather data at 15-minute intervals and delivers related crop, human, and animal specific decision support through the AgWeatherNet website for the benefit of the taxpayers of Washington State. Registration and access to this publicly available portal is free.
On June 27, 2023, the Washington State Department of Labor and Industries (L&I) adopted updates to Outdoor Heat Exposure rules to prevent heat-related illness and reduce traumatic injuries associated with heat exposure, effective July 17, 2023. The adopted rule for agriculture (WAC 296-307-097) includes requirements for shade, rest, and acclimatization, and lowers the temperatures at which some preventive actions must be taken. The requirements are in-effect year-round, whenever workers are exposed to outdoor heat. The Washington Department of Labor and Industries webpage has more details about these requirements.
Among the tools provided through the AWN web portal is the recently updated “Worker Heat Awareness” model page, developed in collaboration with the Pacific Northwest Agricultural Safety and Health Center (PNASH) and the University of Washington. The portal delivers timely information to workplace supervisors and workers about weather station-specific heat stress situation tied to weather forecasts and pertinent actions that can be taken to reduce the risk of heat illness, as summarized from the PNASH’s Heat Education and Awareness Tools (HEAT). The web page and HEAT resources are available in both English and Spanish. They detail best practices that are aligned with Washington State Outdoor Heat Exposure rule for agricultural workers (WAC 296-307-097).
To access the worker heat awareness model, registered users can sign in to AgWeatherNet, select “Models” from the left-hand menu, and then select “Human” in the expanded list of options, and choose “Worker Heat Awareness” from the list of available tools. As the web page refreshes, users will find a form where any of the available weather stations can be selected, along with an option to choose a time range of interest. By default, the tool will display data starting with the current date with added forecast temperatures specific to the selected station(s).
The output chart has air temperature plotted against the range of temperatures defined to indicate various levels of risk (see example below). The white shaded area of the chart indicates low risk, and as risk of heat illness increases, the color of the shaded area gets darker until ‘Extreme Risk’ indicated by a maroon color.
Registered AWN users can also sign up for automatic push notifications to their email or text message address based on a selected risk threshold at the station or stations of interest. To create a new automated alert notification, users can click on the “My AWN” item on the left hand menu, select the “Alerts” option, and then click the “plus” (+) icon to add a new alert.
After clicking the icon to add a new alert, a form appears allowing a user to set the name of the alert, choose the appropriate weather station, set the alert type (e.g., worker heat awareness) and the threshold at which they wish to be notified, as well as the delivery method and address.
Once the form has been completed and the user clicks the ‘Add/Update’ button, the alert becomes active, and the AWN system monitors the conditions at the selected station and will email or push a text message alert if conditions are detected to extend into the risk area defined by the threshold the user has set. Any resulting notifications sent to the user will have specific information on the recommended mitigation actions to take.
Specific actions generally assume that groups of workers are performing moderate physical work and are not wearing non-breathable clothing or personal protective equipment. For example, harvesting tree fruit is considered moderate physical work. An air temperature of 90°F (32.2°C) corresponds to the American Conference of Governmental Industrial Hygienists (ACGIH)® Threshold Limit Value®, which is designed to maintain human body temperature within a normal range under certain conditions. Extreme risk is defined as an air temperature of 100°F (37.8°C) or higher, high risk is 90°F to <100°F (32.2°C to <37.8°C), and moderate risk is 80°F to <90°F (26.7°C to <32.2°C).
The AWN web portal has linked several additional resources, including links to the PNASH Center Heat Education and Awareness Tools (HEAT), the “Be Heat Smart” resource from the Washington State Department of Labor and Industries, as well as workplace posters addressing Symptoms and Treatment for Heat Illness, Risk Factors for Heat Illness, Adjusting to the Heat, and others.
The HEAT toolkit has been developed in collaboration with agricultural workers and educators, to promote workplace safety and health in agriculture. The Toolkit provides a training guide for the identification, prevention, and treatment of heat illness and is available in both English and Spanish. It includes worksite posters and interactive educational materials for workers. The facilitator’s guide and curriculum provide a comprehensive approach to heat illness prevention by addressing risk factors for agricultural workers at the individual, workplace, and community levels.
Links for all HEAT materials are freely available for digital (pdf) download. The same materials are also available in print and can be purchased in bulk through the PNASH print and ship storefront. Small employers, trainers, and educators can print one FREE HEAT Toolkit (value of $35) with promo code. Please email pnash@uw.edu or call (206) 616-1958 to request a promo code.
Use of this product is voluntary, not designed to meet all requirements of the Washington State Outdoor Heat Exposure rule, and does not create or modify legal obligations. The content of this product page is not intended to be a substitute for professional medical advice. Individuals should seek the advice of a qualified health provider if there are questions about heat exposure and health effects.
Acknowledgements
This product was developed by AWN in collaboration with the Pacific Northwest Agricultural Safety and Health Center and the University of Washington with funding from Washington State Department of Labor and Industries SHIP Grant program. The authors acknowledge contributions from community, industry, and agency partners and the HEAT team: June Spector, Maria Blancas, Sarah Fish, Dennise Drury, Pablo Palmández, Jen Krenz.
