The height upto which a liquid rises in capillary tube, is given by:-
h = 2scosθ/rγg
Now, as the surface tension(s) of hot water is less than that of cold water, when a capillary tube is immersed in hot water, it expands. Therefore, its radius increases. As 'δ' decreases and 'r' increases. therefore the height of capillary size(h) will be smaller in hot water than in cold water.