<human>: In 2002, I had a mechanical heart valve put in to replace my aorta which had an aneurisym in it (caused by Tachasus and giant cell arteritis.  I am now 49.  I cannot remember what temperature is too cold or too hot outside for me to be outdoors.  Can you please answer this for me?  Thanks you!!!
<bot>: Hello, Brief answer: As long as you take your blood thinners and your INR level is within normal range, nothing to be worried about. Explanation: My opinion is that after mechanical valve replacement the most important challenge is to keep your clotting profile within acceptable level, that means international normalized ratio or INR level between 2and 3 roughly, anticoagulants is a must and that is more important. Too cold atmosphere may predispose to slow blood flow and tendency to clot, but you need to take care of your medication. I suggest my patients the following: Follow up your clotting profile, avoid missing doses or adding Chat Doctor.  The information provided by you is not sufficient to provide a good opinion. If someone comes to me with this condition I would ask them about your last INR level and the medications you take. Conclusion: I suggest you check your INR. Hope I have answered your query. Let me know if I can assist you further.