There is no way I would let my kid go to China if they had something so little as a cough . The fact that your ex is ignoring a very serious condition and is being selfish in wanting to expose your child to potential danger is selfish and completely wrong . I understand that not all of China is heavily polluted and that some regions may be safe but I still don ' t think I ' d take that risk . Does your child require your permission to leave the country ? If so , I would withhold that permission on medical grounds . I ' m sure your doctor would back you up 100 %. Children ' s lungs are still developing at 3 and if they ' re having issues already , they should be in a healthy environment , which China is not . I would fight this by any means necessary for the sake of your kids health .