6 doctors weighed in:
Why do I feel faint when I get up quickly when its hot?
6 doctors weighed in

Dr. Hesham Hassaballa
Internal Medicine - Pulmonary Critical Care
1 doctor agrees
In brief: Not enough fluid
When you get up quickly, many times the blood in your feet take time to get to the heart.
So, you can feel faint for a bit until the blood goes to your heart and then your brain. Add heat, and it can be worse because you are probably dehydrated. So, if this happens, make sure you have enough fluid. If it is persistent, see your doctor.

In brief: Not enough fluid
When you get up quickly, many times the blood in your feet take time to get to the heart.
So, you can feel faint for a bit until the blood goes to your heart and then your brain. Add heat, and it can be worse because you are probably dehydrated. So, if this happens, make sure you have enough fluid. If it is persistent, see your doctor.
Dr. Hesham Hassaballa
Dr. Hesham Hassaballa
Thank
Dr. Robert Kwok
Pediatrics
1 doctor agrees
In brief: Head has less blood
A person who gets overheated will automatically dilate (widen) the blood vessels in his skin so that more blood will flow to the skin.
His body does this in hopes of cooling him down, just like the elephant who sends more blood to his ears to cool his body down. The person, however, feels lightheaded and may faint because there is not enough blood flowing his brain (too much blood is in the skin).

In brief: Head has less blood
A person who gets overheated will automatically dilate (widen) the blood vessels in his skin so that more blood will flow to the skin.
His body does this in hopes of cooling him down, just like the elephant who sends more blood to his ears to cool his body down. The person, however, feels lightheaded and may faint because there is not enough blood flowing his brain (too much blood is in the skin).
Dr. Robert Kwok
Dr. Robert Kwok
Thank
Dr. Jay Park
Pediatrics
1 doctor agrees
In brief: Low blood flow to...
Transient low blood flow to brain makes you feel faint.
In hot atmosphere, blood vessels in extremities are dilated resulting in peripheral pooling of blood. Getting up quick further compromises blood flow to brain.

In brief: Low blood flow to...
Transient low blood flow to brain makes you feel faint.
In hot atmosphere, blood vessels in extremities are dilated resulting in peripheral pooling of blood. Getting up quick further compromises blood flow to brain.
Dr. Jay Park
Dr. Jay Park
Thank
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