If the hot season turns cold, taking a bath will be something hard. Through the hot water that comes out from the shower head will decrease your burden. This will happen if your shower head and other things are functioning well but if it is not like that, you may not take a bath every day.
Once you do this, you will not have proper hygiene and you are more prone to many skin diseases that will let you pay more than repairing the valve and the shower head. The warm water that you are using when you are taking a bath is made possible by the mixer showers. The work of this is to mix hot and cold water in order to make warm water.
If there is no warm water coming out from the shower head, it means that there is something wrong with the mixer shower. You have to buy another so that you can use warm water. This is the thing that is mainly responsible in making that so if there is something wrong with this, you must purchase one now.
Aside from the mixer shower, the cause of your problem may be on the pipes connecting to the reservoir of the cold water and hot water. The water cannot pass to the pipe until it reaches the mixer shower because of the so called blockage. This should be solved as early as possible.
You can ask help from a plumber. The plumber is considered as an expert when it comes to pipes so he can help you out. As an alternative, you can boil cold water and after that you can mix it to a pail of cold water to have warm water. This will protect you from feeling cold in times of taking a bath. Therefore, the best thing that you can do is to look for a plumber. You should not allow somebody to do the job who does not have the skills, you are just adding something bad to your problem.