Heat Stress / Emergencies. Every year, thousands of workers become sick and die from heat exposure on the job. These illnesses and deaths are preventable. Workers exposed to hot and humid conditions are at risk of heat illness, especially those doing heavy work tasks or using bulky protective clothing and equipment. Some workers might be at greater risk than others if they have not built up a tolerance to hot conditions, are in poor physical condition, are older, or if they have heart disease, high blood pressure, or are taking certain medications.