Hoping you've had all your questions answered. I just saw this.
Our little traveling companion has been a fulltime traveler since birth. We've been in subfreezing temperatures and desert heat. The most important thing is to make sure the little one is hydrated in both situations.
As far as cold, someone has already mentioned the portable Mr. Buddy heater. We use this but only in the mornings and evenings as we are either getting into or out of our sleeping bags. We turn it on for about a minute in our RTT and it heats it up like an oven. Then we shut it off and get changed in the warmth that it has produced.
Don't skimp on the little one's sleeping bag. Our son uses a Big Agnes Lost Ranger bag and it has served him very well. Also make sure that your little one is wearing a hat at night. Most heat escapes from the head and it is typically the only part that is uncovered during the night.
For babies, a baby carrier or sling keeps the baby close to an adult for body heat.
Use extreme caution with any heat source (fire or portable heater) as they tend to crawl or toddle towards the light. I typically place myself between our son and any heat source unless I'm physically holding him.
Let me know if you have any specific questions. Happy to be a resource. And lastly, good on you for taking your little one out exploring! ~ Eric
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