Kidneys need warmth. It is not without reason that motorcyclists, for example, wear a kidney belt. It is advisable to protect the kidney area in summer and winter. Vests are an issue. Sleeping naked is generally a problem because you don't notice when and where your body gets cold. Tying a light jumper around your waist in rooms with air-conditioning is advisable. Even in summer and refrain from consuming drinks from the fridge.