Tropical illnesses are those that prevail in or are exclusive to regions with tropical and subtropical climates. Disease transmission tends to be less frequent in temperate areas, largely due to the presence of a colder season that regulates the insect population by inducing hibernation. Insects like mosquitoes and flies are the primary carriers or vectors in many cases. These insects might harbor a virus, bacterium, or parasite that can infect both humans and animals. The transmission of the majority of these diseases occurs through insect "bites," which also facilitate the exchange of infectious agents through the exchange of blood below the skin's surface. Vaccines are not yet accessible for the majority of these diseases.