ARLINGTON — As temperatures climbed into the upper 80s over the weekend and heat advisories made news, north county residents sought relief in the area’s waters.

While the sun was out at Twin Rivers Park, the usually crowded baseball, soccer and disc golf fields were almost completely empty. No, the park was crowded for other reasons. Some families sought comfort with a shady picnic near the tree line, while others trekked through the woods to the bend in the Stillaguamish River.

Where the forks meet — the shore of Haller Park visible across the way — Waltet Loayza watched attentively as his children Michelle and Gian floated downstream on inner tubes with their friends Aliah and Devin. While parts of the river are shallow enough to wade across, the water gets deep fast, deep enough that one swimmer across the river dared to jump from the overpassing train bridge.

Meanwhile at Twin Lakes near Lakewood Crossing, the beaches were packed as families grilled out on the small pits buried between trees and others sought relief from the heat in the lake.

With the sandiest section of the juvenile fishing pond absolutely packed with swimmers, siblings Alexis, 8, and Thomas Brooks, 6, made friends at the smaller beach a little further down the shoreline in the narrow gap of shallow water that unites the lakes, bobbing around under the watchful eye of their mother and stepfather who floated nearby on individual-sized tubes.

With two new friends of a similar age, Alexis took turns practicing dog paddling out into nearby water after floatation devices.

The Center for Disease Control recommends a designated adult supervise all children swimming in or playing near water and advocates a buddy system for all swimmers to prevent water-related injuries. Swimmers are also reminded not to substitute inner tubes or other water toys for the safety of a lifejacket.

Swimmers and boaters at Twin Lakes can take advantage of the county’s lifejacket loaner program, with jackets for children to adults available to borrow in the wooden locker located behind the changing rooms.

More tips about swimming safety are available at www.drowning-prevention.org.