Jannik Sinner battles exhaustion, heat rule to avoid Australian Open upset

While large swaths of the U.S. faced ice and snow this weekend, tennis stars in Australia battled extreme heat.

The conditions took a noticeable toll on Italian Jannik Sinner, who tried to stretch through apparent cramps and needed the assistance of an air-conditioning tube during the third round of men’s singles at the Australian Open.

Nearly 100-degree temperatures in the third set appeared to spark Sinner’s cramping issues. Sinner struggled to deliver a high-velocity serve in the third set...