Workers in the intervention group will receive the HEAT training, and supervisors in the intervention group will receive the HEAT awareness application and training on how to use it.

The comparison group will not be offered HEAT trainings or the HEAT awareness application. They will be offered an alternative training on another topic.

HEAT training will be delivered to agricultural workers by research staff in this study in the spring. HEAT training uses interactive approaches to engage participants and posters with visuals. Training covers types of heat-related illness and treatments, risk factors, appropriate clothing and hydration, and keeping cool in the home and community. The HEAT awareness application was developed in collaboration with Washington State University's AgWeatherNet Program to notify supervisors signed up for the service about hot weather conditions that might increase the risk for adverse health effects for workers. The HEAT awareness application is designed to allow subscribers to select weather stations of interest and view current heat indices as well as maximum daily heat indices forecasted over the following week. This information is coupled with information about health effects and prevention of adverse heat health effects. Materials are provided in English and Spanish.

Heat symptoms will be assessed using a short survey conducted in Spanish or English that includes questions about heat-related illness symptoms experienced over the past week. Participants will select one or more symptoms (or select 'none') from a list.

The body's physiological response to heat stress. Core body temperature (degrees C) will be estimated using personal baseline temperature and continuous heart rate during work shifts on several days.

Short set of multiple-choice questions based on key points addressed in the one-hour training on recognition, treatment, and prevention of heat-related illness.