RF isn't heat, per se, it's radio frequency energy. I've been burned (contradicting myself already) by RF Energy, it's not like it's a soldering gun type heat, it's an RF effect.
I searched for "cryoablation of arrhythmias NIH" (National Institutes of Health) and found the following link. There are many more links found this way as well. Hope this is of some use to you. I enjoy researching, if you post back, I'll be glad to try to answer your questions. As fast as being awake, I understand that varies by circumstances, but the anesthetics they have today make conscious sedation possible and is so profound that it is unlikely you'd be concerned during the procedure. www.ncbi.nlm.nih.gov/pubmed/15596960
"Catheter cryoablation is a safe and clinically effective method for ablation of atrioventricular nodal reentrant supraventricular tachycardia. Although the acute procedural success rate of catheter cryoablation for this arrhythmia may be slightly lower than that reported for radiofrequency ablation, it has an excellent safety profile, with no reported instances of inadvertent atrioventricular block requiring implantation of a permanent pacemaker." (Very interesting, I've never heard of cryoablation before, but have read of the AV issue with RF Ablation).
Using this technology, one can perform reversible cryomapping, which helps to identify suitable ablation targets while identifying sites where cryoablation should be avoided. For patients with midseptal and parahissian accessory pathways, in whom the risk of producing inadvertent atrioventricular block is substantial, catheter cryoablation is a safe and effective alternative to radiofrequency ablation. Catheter cryoablation of common atrial flutter causes much less patient discomfort than radiofrequency ablation, with excellent acute and long-term efficacy. Catheter cryoablation also can be used to isolate the pulmonary veins during ablation of atrial fibrillation. As compared with radiofrequency ablation, the risk of acute thromboembolic complications and of pulmonary vein stenosis appears to be lower with cryoablation."