You are more likely to catch colds during winter than in summer. Cold weather itself doesn’t cause colds, but it helps them spread. Many viruses, like the flu and COVID-19, thrive in cold, dry air. These conditions keep viruses infectious longer and help them multiply faster.
Cold weather also weakens the immune system, making it harder to fight infections. Still, viruses and bacteria—not the cold—are the real cause of illness.
Dengue fever is the world’s fastest-spreading mosquito-borne virus. Its range has extended drastically over the last six decades. Much of this transformation is the result of climate change.
Ebola is a virus that affects humans and causes high death rates. It is highly contagious and resists many current treatments.
Avian flu is a viral disease affecting wild birds and poultry. Though rare, it can spread to humans and other animals.
