A return of excessive-heat advisories in the Valley combined with a holiday weekend is prompting many to head out of town for somewhat cooler climes.

Department of Public Safety spokesperson Bart Graves says Interstate 17 will be particularly busy and advises motorists to avoid the rush if possible.

“You don’t want to leave town at the same time everyone else is leaving town and we expect a lot of traffic on I-17 and sometimes we have such a heavy volume of traffic that it slows considerably where it actually stops. There’s just too much volume,” he said.

Popular boating destinations like Lake Havasu are expected to be packed with visitors.

Kyler Cox with the Mohave County Sheriff’s Office said law enforcement will increase patrols.

“Labor Day weekend is kind of the last hoorah for boating. We have deputies out there who are proactively looking for signs and symptoms of operators who are operating under the influence of alcohol and or drugs,” he said.

Emergency crews in Pima County on Friday responded to two hikers who suffered heat exhaustion. Officials advised caution to others who plan to head out on trails this weekend.