Suspension trauma, also known as orthostatic intolerance or harness hang syndrome, is a deadly condition caused by a long period of restricted blood circulation. Symptoms include:
Lightheadedness Palpitations Tremulousness Poor concentration Fatigue Nausea Dizziness Headache Sweating Weakness or fainting upon standing Unconsciousness
Orthostatic intolerance first begins when a worker experiences a fall and is suspended above the ground, typically when using a fall arrest system. While suspended, a worker may become unconscious and the length of suspension combined with venous pooling (blood collecting in the veins) could result in death. Such fatalities can occur in less than 30 minutes and even as little as 10 minutes. OSHA mandates that rescue be made within 4-6 minutes.