humidity – n. the amount of moisture in the air
athlete – n. a person who is trained in and good at sports
heat stroke – n. a serious medical condition caused by body temperatures that are too high
endurance - adj. the ability to do something difficult for a long time
triathlon – n. an endurance sport that has three parts: swimming, bicycling and running
marathon – n. a race that is about 42 kilometers
adapt –v. the ability to change to deal better with present conditions