Why would the temperature gauge run high? on 2008 Hyundai Tucson

Gauge will hit the high end and then go back down to about half way. Also, the a/c will blow cold at first, then blows hot. Are these issues related?

Asked by for the 2008 Hyundai Tucson
1 answer 2 comments
Yes they are related. You need to immediately check the coolant level (when vehicle is cold) do not remove cap when hot. If level is low fill it to correct level and have the cooling system pressure checked. If level is not low have it checked by a repair shop ASAP.
Thank you for your help! I'm taking the vehicle down to the dealership to have it looked at. Do you think maybe there might be a problem with line/hose?
ALSO HAVE RAD. COOLING FANS CHECKED, WITH CAR RUNNING WITH AC ON
AND BLOWER FAN ON HI, RAD. FAN OR FANS SHOULD START RUNNING
WITHIN 2 MIN. LOOK AT FANS TO SEE. HEED FIRST ANSWER ALSO.