Wind strips away the thin layer of warm air around your skin and speeds up heat loss: this is wind chill. Using the index adopted by Météo-France, developed in 2001 by the Canadian and US weather services, -5 °C with a 30 km/h wind feels like -13 °C on bare skin. One subtlety: wind chill describes living skin, and wind can never cool an object below the actual air temperature.
Chlorine on its own is fairly gentle. But when it combines with urine, sweat and other grime from swimmers, it forms chloramines, which cause stinging eyes and that classic 'chlorine smell'. A well-kept pool barely smells at all. Shower before you swim and never pee in the water.
Muscle mass slowly shrinks with age, putting independence at risk. But in 1990, a study had nursing home residents aged 86 to 96 train their legs for eight weeks: their strength more than doubled. Muscle responds to training at any age. Getting up from a chair without using your hands is already an exercise.