The feet are sweating most in summer and that is the reason why the risk of getting a fungal infection in summer is the biggest. You should try and walk barefoot as much as you can, but since that is not possible, you should take care of the hygiene of the feet. Also, you can try the following natural treatments:
You can mix hydrogen peroxide with water and soak your feet in the mixture. This way you can kill the infection and furthermore, prevent it from spreading. 100 milliliters of 3% pharmaceutical grade hydrogen peroxide should be added in 1 liter of distilled water. This mixture should be used to soak your feet in, every morning and night for 20 minutes.
As previously mentioned, you should walk barefoot as much as you can and you should also avoid nylon and synthetic shoes and socks. But if you have to wear closed shoes, you can destroy the bacteria by making a mixture of cold water and sodium bicarbonate (3:1) and apply it daily.
Corn starch is a great absorber so it can be used for making a paste against moisture in the feet and against bacteria and fungi. Make a mixture of half a teaspoon of corn starch and a little warm water. Heat the mixture in 220 degrees until it becomes darker. Clean your feet and then apply the mixture, leave it for 1 minute and then wash it away.
Yogurt contains a lot of good microorganisms and the live bacteria –acidophilus which is a great medicine for infections in the area between the toes and the nails. Those microorganisms kill all the infections caused by fungi. You can heal your feet by soaking them in yogurt or just simply rub yogurt over them and after it is dry, wash it off with water.