Underwent ASD Closure Treatment. Get Shivering If The Weather Is Cold. Not Able To Sit In The Computer Lab. Reason?

Hello Doctor, I have undergone ASD Closure treatment through angio. The device used for me was 30mm Cocoon. I have undergone this in the month of July, 2012. After that if the weather is little bit chill, then I get shivering . Not palpitation just I cannot talk. I am a Professor in a College. In computer Lab the AC will be put in a very low temperature. So my palm become chill and I cannot take class. When I discussed this with my cardiologist , he said this not because of ASD closure and I am the one reporting such a new compliant. When I reported this first, he told me to stop one tablet(I don’t remember the content) but since I am having the same problem. Now I am taking “Sildenafil-20mg 3 times & Clopilet and Asprin-75mg 1 time”. Before undergoing ASD closure, I took Sildenafil alone. At that time also I don’t have such problem. So please text me what may be the reason for this and what I have to do for this. Thank you.