Why do I get red cheeks when it's hot out?

my cheek become red when I travelled in sun shine

its called sun burn

well yes, sun burn, if your face is exposed to the sun. It could also be blood vessels in the face that dilate when you are warm, which gives you the rosy red in your cheeks

I get the same thing - I have fair skin and genetically my face gets beet red when ever I get hot - like people ask me if I'm ok red - it's kind of embarrassing but hey I got out of a LOT of gym classes !
Use sunscreen on your face everyday - like a water proof moisturizer with SPF 15 in it - and if your traveling to where its sunny and hot - keep a bottle of water with in in an atomizer/mister and spritz your face often - help keep it from getting too red - this is how your body cools off unfortunately - the blood rushes to the surface of your skin on your face - you probably dont sweat as much as others though