Temperature

Circulation can decrease, worsening the symptoms of Raynaud’s, diabetes, and joint pain.
Heart Attack - A drop just 2°F can increase blood pressure and the risk of blood clots.
Flu - Experts believe rapid swings in temperatures can weaken the immune system. In addition, the rhinovirus, or common cold transmits better in colder air.

Lung Disease/COPD - Hot, humid weather can make it difficult to breath, especially for those that suffer from pre-existing breathing conditions. Air pollution during warmer weather also contributes to these ailments.
Heat Related Illness - Warm temperatures during the day and night can cause the human body added stress such as heat exhaustion and heat stroke.