That's an excellent and very practical question! As someone who loves spending time outdoors, I've wondered the same thing. The short answer is: recycled plastic benches can get warm in direct, hot sunlight, but they generally do not get as dangerously hot as traditional metal benches and are often comparable to or better than wood in terms of heat retention.
Let's break it down. Recycled plastic lumber, typically made from high-density polyethylene (HDPE), has different thermal properties than metal or natural wood. Metal is an excellent conductor of heat, so it rapidly absorbs and transfers solar energy, becoming too hot to touch. Wood can also get quite warm and may even splinter from the heat. Recycled plastic, however, is a poorer conductor. It heats up more slowly on the surface.
In direct, intense summer sun, the surface of a dark-colored recycled plastic bench will become warm to the touch. You'll definitely feel the warmth, but it's rarely at a level that would cause discomfort or a burn risk like metal. Lighter-colored benches (tan, grey, light green) absorb significantly less heat and stay much cooler. The material also doesn't retain heat for long; once in the shade, it cools down relatively quickly.
Many people find the warmth of a recycled plastic bench in the sun to be pleasantly similar to warm wood—perfectly sit-able. Its non-porous surface also means it won't give you splinters or trap heat in the same way. For optimal comfort, look for benches placed in partially shaded areas or opt for lighter colors if you're specifying them for a sunny location. So, while you might seek a shady spot on a scorching day, you can rest assured that choosing a recycled plastic bench is a comfortable, sustainable, and safe choice for your community park or garden.