A: People with untreated hypertension, heart attack within the previous 6 months, decompensating diseases (edema) of the cardiovascular and respiratory system, congestive heart failure, COPD, chronic liver disease, unstable angina pectoris, pacemaker, peripheral arterial occlusive disease, Deep Vein Thrombosis (DVT) within previous 6 months or known circulatory dysfunction, acute febrile respiratory (flu-like respiratory conditions), acute kidney and urinary tract diseases, severe anemia, Cold Allergenic Phenomenon (known allergy to cold contactants), heavy consumerist diseases (abnormal bleeding), seizure disorders, bacterial and viral infections of the skin, wound-healing disorders (open sores or discharging wound/skin conditions), alcohol- and drug-related contraindications, valvular heart disease, condition after heart surgery, ischemic heart disease, Raynaud’s disease, polyneuropathies, pregnancy, vasculitis, claustrophobia, hyperhidrosis (heavy perspiration) or advanced diabetes.