The PTFE coating on nonstick pans is stable at normal cooking temperatures. But an empty pan left on high heat can pass, within minutes, the roughly 260 °C (500 °F) at which it starts to break down. In humans, the fumes cause a short-lived 'polymer fume fever'. For birds, whose respiratory system is extraordinarily efficient, they are often fatal, even in another room.
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.