Exercise-induced asthma without respiratory heat loss.

It is well documented that exercise-induced asthma is more pronounced when inspired air is cold and dry rather than warm and humid.' 2 The severity of exercise-induced asthma is closely dependent on loss of respiratory heat, needed to warm and humidify inspired air,3 and it has been suggested that airway cooling is the only stimulus triggering postexercise bronchoconstriction.3-7 We present a case of an asthmatic patient who has repeatedly developed exercise-induced asthma while breathing air at body temperature and humidity with no respiratory heat loss.