Just be careful if you believe the itch is the result of something you might be allergic to (e.g., food, or bug bites).
I had several bites from fire ants and ran them under hot water from the bath, which seemed to trigger (or accelerate) a full-body reaction (anaphylaxis?) and a harrowing trip to the emergency room!
Ouch. Don't use heat to combat the symptoms of the bite of any venomous animal or any other one that secrets stuff into your body (mites, mosquitoes, etc).
It's hard to tell people to do things that reduce their blood flow, because it comes with complex side effects; but definitively not do anything that increases your blood flow. (As in, if you are feeling sick, do not eat peppers either.)
Because virtually nobody is allergic to mosquito bites. Accelerating the blood flow/metabolism of someone maybe at risk for anaphylaxis (bee allergy) is extremely dangerous.
But when you have more than a few bites, you probably will not want to do that. Even more if you feel them a lot, and if you are not used to have lots of mosquito bites on you.
I had several bites from fire ants and ran them under hot water from the bath, which seemed to trigger (or accelerate) a full-body reaction (anaphylaxis?) and a harrowing trip to the emergency room!