As Portland spring temperatures soar past 80 degrees Fahrenheit, it feels like it's time for a dip in the ol’ trusty swimmin' hole. Ignore that instinct. You want to think twice before heading out to your favorite spot just yet, says Mike Gasperson, a firefighter and paramedic with Clackamas Fire District. He has responded to dozens of distress calls over the years at local lakes and rivers, where the water temperature can be frigid. “The majority of those calls are swimmers in distress,” Gasperson says. “You jump in thinking the water is going to feel good, but your muscles tense up and it takes your breath away and causes you to panic."

Why wouldn't it be safe to swim if the air temperature is hot? Many rivers are fed by snow runoff from the mountains, creating water temperatures that are far lower than the air temperatures. For example, the Sandy River recently clocked in at 45 degrees, and locations like High Rocks, Barton Park, and Carver Park on the Clackamas River are in the neighborhood of 50 degrees, according to the US Geological Survey, and can easily induce shock. “Even the fishermen are a little gun-shy about getting in the water with waders,” says Dave Selden, a lieutenant with Corbett Fire District. 

If the pros aren't going in, you shouldn't either. We rounded up best practices: 

Look before you leap. Your favorite river spot likely is not the same as when you last swam there, says Selden. Dangers often lurk just below the surface, such as new logs and rocks. Take the time to get your bearings, and know that a placid surface can hide a rip-roaring current just below that's ready to sweep you away.

Leave pool toys at the pool. “Odds are they're just going to pop, and then you’re going to be in the drink,” says Gasperson, who often responds to situations involving people not using the proper equipment, frequently at sites like Milo McIver State Park, and the Clackamas River between Barton and Carver.

Wear a damn life jacket. Even if you're a great swimmer. Yes, you. “It’s a medical truth that when water is cold you can go into hypothermia pretty quick,” says Selden. In hypothermia, the body loses control of muscles and numbness can set in which makes it hard to swim, especially in fast moving water.  Wearing a properly fitting life jacket solves most dangers posed by swift and cold water.

Consider sobriety. A harsh reality: after a couple of drinks, you aren’t as good of a swimmer as you think you are. “It changes your outlook and what feels comfortable versus your actual capabilities," says Sgt. Stephen Dangler, a member of the river patrol unit at the Multnomah County Sheriff’s Office, which is responsible for safety along 110 miles of Portland waterways. While Dangler preaches sobriety of boaters and swimmers on the water, he knows that people are going to enjoy their beverages. With that mind, Dangler says that operators or “captains” of boats should keep in mind that they are responsible for the well-being of everyone on their vessel.

If things do go catastrophically south, remember the water safety acronym that rolls right off the tongue: RETHROG, for reach, throw, row, go. After calling 911, try to reach out to the victim with some sort of large stick or paddle. If that doesn’t work, try throwing a life jacket or a rope. The last option is to use a small watercraft—such as a raft, kayak or stand-up paddleboard—to row out to someone in need of rescue. Professional rescuers say that you should never put yourself in harm’s way in order to rescue someone, a task best left to the pros. 

All of this, of course, is generally avoidable with life jackets. “It might not seem like the coolest thing at the time, but it’s definitely a cooler alternative to drowning,” says Gasperson.