Dont agree. Butane pressure regulators are set for the hottest country ( anywhere near the equator) and the bottle left in direct sunlight. On the other hand if the temperatures drops very low a lot of gas companies mix the two gasses 50/50 so it keeps flowing in the winter."I refill my blue 4.5 calor butane from a large red/orange propane. You can get the fittings from Ebay."
Do NOT refill a BUTANE cylinder with PROPANE. The valves and regulators on the butane cylinder are not designed for the higher pressure of propane.
Only refill with the type of gas originally supplied in the bottle.