What is a key concern when humidity levels are 70% or higher?

When humidity levels are 70% or higher, heat stress becomes a significant concern. High humidity increases the body's difficulty in cooling itself through evaporation of sweat. Under such conditions, sweat does not evaporate as efficiently, leading to a rise in body temperature. This can result in a range of heat-related illnesses, from heat exhaustion to heat stroke, which can be life-threatening without prompt treatment.

In environments where humidity is high, the risk of overheating is heightened for individuals engaged in physical activities, particularly for those involved in firefighting or other strenuous occupations. Monitoring temperature and humidity levels is essential to implement preventative measures and ensure the safety and well-being of all personnel on the scene.