My son is 12 and is constantly hot, this is not new, it's been happening for 4 years. He can't exercise in hot weather or he gets heatstroke, he will be on his netbook in the dining room for 20 minutes - no heating and 2 windows open and come into the living room spent - red faced, feeling sick and just too warm. He sleeps with a fan on him at night and window open, could this be something serious? Can't get a face to face doctors appt because of lockdown.