You can shower and bathe while you fast

When you fast, you can bathe, shower, or pour water over a part of your body or over all of your body to cool yourself down. This is not disliked. There is nothing wrong with it. The evidence for this is the following hadiith:

Narrated A Companion of the Prophet:

Abu Bakr Ibn Abdur Rahman reported on the authority of a Companion of the Prophet (sallallaahu alayhi wa sallam): I saw the Prophet (sallallaahu alayhi wa sallam) commanding the people while he was travelling on the occasion of the conquest of Mecca not to observe fast. He said: Be strong for your enemy. The Messenger of Allah (sallallaahu alayhi wa sallam) fasted himself.

Narrated Abu Bakr:

A man who narrated his tradition to me said: I have seen the Messenger of Allah (sallallaahu alayhi wa sallam) in al-Arj pouring water over his head while he was fasting, either because of thirst or because of heat.

[Sunan Abi Dawud Hadith No. 2365]

فيه دليل على أنه يجوز للصائم أن يكسر الحر بصب الماء على بعض بدنه أو كله ، وقد ذهب إلى ذلك الجمهور ولم يفرقوا بين الاغتسال الواجبة والمسنونة والمباحة

Those who have said it is disliked have used a weak narration attributed to Ali (may Allaah be pleased with him). Others have said it goes against the "wisdom" of fasting. The premise of both is baatil because it goes against an authentic hadiith.

Reference(s):

عون المعبود