You need to be cautious with your cloths and travel equipment while making your travel plan to Bhutan. You need to know the season and weather condition before packing your things while traveling in Bhutan. The temperature and climatic condition varies in various regions of the country due to geographical condition and altitude differences. You therefore need to be very careful about selecting your dresses during your trip to the kingdom of Bhutan.
If you are trekking in the months of October, November, December, January and February, make sure that you have thick overcoats and tweeds to protect yourself from cold. It gets very chilly during the winter in the high altitude regions. The months of April, May, June, July, August and September are warmer and carrying light cloths is highly recommended. Carrying the rain gears are highly recommend during the raining season (June-August).
Bhutan being a religious country following the proper dress etiquettes would be a good idea. You are advised to avoid shorts, skirts, tight clothing while visiting the religious sites like monasteries and temples. Any clothing that express vulgarity is strictly prohibited while traveling in the temples and monasteries. You are also advised to remove the sun caps if you are visiting temple of Dzongs.
Most of the trekking gears and equipment you need to carry during the trips will be updated by the tour operator. Some trekking gears may be provided by the tour operator you are booked with. Some of the budget hotels may not provide you with the basic stuff like toothbrush, soaps, toothpaste, towels etc. You are recommended to carry these stuff by yourself. You are also advised to carry cameras, handy cams, and cellphones during your visit to Bhutan.