Stay calm and allow your body to get accustomed to the high altitude and low oxygen levels.
Do not run, scream or get euphoric in excitement.
Be prepared by carrying heavy winter clothes including hats, gloves and woollen scarfs. Gangtok maybe the last chance for you to purchase these before heading up.
Do not underestimate the weather and the cold winds awaiting.
Make timely travel arrangements and stick to the schedule to comply with the entry and exit timings of multiple check posts.
Do not delay your departure time as it can cause inconvenience to comply with the check post timings.
Carry an oxygen can that is certified and IP grade for personal use. O2 Himalaya is the number one oxygen manufacturing company of Sikkim that is going to be your best friend in your time of need. Oxygen cans are personal. Try not to share a breath with someone else. It can cause bacteria and virus spread.
Carry: Voter ID/ passport, passport size photos (along with several photo copies) to present at the check posts. Do not carry Aadhar Card alone as it is not accepted in the check posts.
Stay hydrated and carry ginger chews & candies to quell altitude-induced stomach nausea. Inform to your driver immediately in case you feel giddy, nausea or light-headedness. Do not drink alcohol, avoid smoking or taking sleeping pills as it increases the symptoms of altitude sickness.