Swollen and tight feeling leg

Currently on a trip with lots of walking and it’s been pretty warm. I’ve been doing pretty well (breaks and lots of water and electrolytes) but today I noticed a tightness feeling in both legs then just one. Looked later and my one leg appears to be a little swollen and it feels tight? I’ve never had this happen before but I’m assuming it’s from the heat and the walking. Does anyone have any solutions or advice on how to handle this and prevent it? I thought about wearing my compression stockings to bed tonight and continuing to wear them tomorrow during the day when continuing to walk.

Anyone else experience this? Or anything like it?