Improving health and wellbeingThe researchers also assessed how canals affect thermal comfort during hot weather. Their modelling showed that incorporating the cooling effect of canals reduced the number of hours classified as posing moderate heat risk by around 58%, while hours of high heat risk fell by around 74%. In many locations, canals eliminated periods of extreme heat risk altogether, although the researchers caution that this is partly counter-balanced by rising humidity, which also influences people's comfort during hot weather. "The cooling effect is modest on an average day, but during heatwaves it becomes much more significant, reducing nearby temperatures by more than two degrees in some locations. Even relatively small reductions like these can make an important difference to people's health and wellbeing during periods of extreme heat."