Your friend has been exercising vigorously in hot weather and begins to have very painful cramps in his thighs and calves, what should you know about this condition? a. these are heat cramps and are a warning sign of a heat emergency; give first aid care and call 911 if the condition worsens. b. this is a common problem; it is okay to continue the workout as soon as the cramp has stopped. c. your friend has torn his hamstring; call 911. d. none of the above.