The only diference between Ashkenazim and Sefardim is when all halachos start, for Ashkenazim its on Rosh Chodesh Av While for Sefardim its the week of Tishu B’Av.
As to taking a shower it depands on many things (like if you work in the outside heat, are you specialy sensitive, is it very hot, do you have a medical condition etc.) so one should ask his LOR.