Diabetes, sweating. Diabetics would be more susceptible to fungal infections as well as people on long term steroids and immunosuppressive drugs. High s hook and college wrestlers can easily catch fungus because of close personal contact. Sweating on the feet can create a good environment for fungus to develop.
Moisture. There are many different types of skin "fungal" infection. The most common are tine pedis (athlete's foot), intertrigo (yeast in the groin area), and tinea corporis (fungus on the body). A moisture, warm environment tends to make fungus thrive, so keeping the area dry is important. Use fungal powder and dry well after showering will help reduce the moisture in the area.