As Dr Amlendu Yadav flicks the switch, the large pipe starts gushing water while he shovels ice into the tub. In two minutes, it is full, ready for the next patient in his newly created emergency heatstroke unit at Ram Manohar Lohia hospital in the Indian capital.
The point, he explains, is speed. Heatstroke patients need to be dunked in the bath the moment they arrive at the hospital if they are to stand a chance of surviving.
