Tipping your head back is an old reflex worth dropping: blood runs down your throat, gets swallowed and can make you feel sick or vomit. The NHS advises sitting down, leaning forward and firmly pinching the soft part of your nose, just above the nostrils, for 10 to 15 minutes while breathing through your mouth. If the bleeding won't stop, or follows a blow to the head, get medical help.
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.