Is hot water or warm bad for acne condition?

No: Just as long as it isn't too hot, you don't need to be dealing with burns on top of acne. Warm/hot water will cause some dilation of skin pores making it a little easier to cleanse and remove debris. This may help reduce the number of new acne lesions. Washing with a benzoyl peroxide or salicylic acid wash often adds to the improvement. See your gp if you are having problems.