Temperature has little, if anything to do with vein visibility. You can see veins at any given time (usually), if you look at your wrist or anyplace the skin is thin.
Veins are invisible when the skin is cold while if the skin is warm you can easily see it or it pops out.
When you look underneath your tongue, you can see purple veins. So yes, there are veins in the tongue.
no
When you are cold your heart pumps more blood so you have higher blood pressure
Look at the back of your hand. Do you see some branch-like blue things showing? Those are your veins.
You should apply cold compresses to varicose veins. Heat dilates blood vessels, so the veins may appear more visible after a hot shower. The cold compress will cause the veins to temporarily contract, making them less visible.
See a doctor.
You will need a dermatologist for varicose veins. Your regular Doctor can refer you to a specialist.
Pack it with ice. The cold will repel the blood.
Ofcourse not, you don't see them, your fingernails can't bleed and the body doesn't see a need to put nerves in it.
Epidermis stem veins stomata
Because you are light skined