Power supply units are often large relative to the outlet and block access to adjacent outlets in a power bar.
A simple solution is to use 1/2 ft or 1 ft (15cm, 30cm) power extension cords to keep all outlets in a power bar available.
Yet my hunch tells me that doing so increases the fire risk.
Could someone with actual knowledge in the matter pitch in with an opinion?
Does unblocking power bar outlets through short extension cords increase fire risk?
I am not considering an exotic setup (daisy chaining, forking, etc..), nor will the wattage be high (laptop and paraphernalia, at most a stereo amplifier in one slot). The question is whether this increases the risk of fire. The idea is that there are now many more places where rust, or just a poor contact, will happen. And rust/poor contacts cause heat that can spiral to something sinister.
Update
I marked Isherwood's answer right, but thanks to Harper's and Owain's answers I see now that there is an abundance of options to avoid even a small increase in risk. One key keyword is "metal". Search, for example, for "metal power strip" to see ones where right angle plugs will not occlude adjacent outlets. Some have a larger inter-outlet spacing. The challenge is find one not painted yellow.
Best Answer
Yes, but negligibly.
Any connection increases fire risk by increasing the chance of heat buildup due to resistance, sparks due to arcing, etc. The question is how much, and the answer is not much.
Since you already probably have dozens of such connections in your home (including such high-current things as a microwave and kitchen range), and since most of these are low-current devices, I see no reason to be concerned.
One caveat would be the potential for heat buildup around the transformers. They're normally held captive by wall outlets or power bars and not likely to end up in a heap on the carpet. In combination, many transformers without good cooling airflow could overheat. Don't let that situation arise.
Make sure all hardware is in good working order and be happy.