Emergency shower option

Has anyone ever provided a temporary hot water shower for a tenant? If so, what type? I thought maybe something that’s used by campers might be suitable.

Boiler has packed up and is going to take some some to have replaced so want to see if can sort something as a temporary measure.

i fit in my places an electric shower over the bath with a screen so if boiler goes at least they can have a shower. This is a permanent solution and I put in 10 mm electric cable back to the fuse board