Forgot to add to my posting above. That the prices for Rupa's Realm Sauna are likely to be £2 for a shower only, £5 for a sauna session, and £10 to £15 for a full duration festival pass. The hot showers are cubicles with privacy curtains.
Regarding Sam's Sauna and showers. They will not be there this year.
Rupa's Realm Sauna(including showers) will be making their debut at Glastonbury this year. Replacing the absence of Sam's Sauna. They will be based in the same location of Undle Ground. They will also be a cheaper alternative to the more expensive Lost Horizon Sauna.