Why do my hands get red blotches in the skin that don't itch and aren't bumpy I know it's not a rash. It always happens at school when my hands are cold or sweaty.?

The red blotches on your hands could be a result of poor circulation or a response to temperature changes, especially when your hands are cold or sweaty. This condition, known as “erythema,” can occur when blood vessels dilate to regulate temperature, leading to temporary redness without itching or bumps. It's usually harmless, but if you're concerned or if the symptoms persist, consider consulting a healthcare professional for further evaluation.