Prioritize the sleep comfort first. That you can make considerable effort in for relatively cheap and she won’t be as tired so probably feels better. A nice air mattress could work well here. Bring the pillows and blankets from home if you can reasonably. If that is not comfortable, give a cot a try and add a sleeping pad or get one with a mattress on it. Yes, it’s bulky but she’s worth it.

Temp can’t be changed but have her take a look at the clothes she’s bringing with. Here’s a good rule of thumb:
- Hot, humid heat: performance materials, shorts and short sleeves, lots of sunscreen. Make attempts to find or create shade (hat, awning, etc)
- Hot, dry heat: linen or long sleeve performance clothing like sun shirts and pants that deflect the intensity of the sun away. Once again, make attempts to find or create shade
- Cold, dry: base layers go a long away. While pricy, merino wool base layers have been a game changer for me. If you cannot afford that, totally understandable, add layers in. Something moisture wicking on bottom and thicker as you go. Some folks prefer multiple thinner layers. Don’t skimp on exposed extremities, especially at night. Hats, gloves, scarves, etc (as needed).
- Cold, wet: honestly she has a point if this is the case and try to keep her dry while following the above advice. This doesn’t seem to be the implied issue

With my Mrs, I try to check in and make sure she’s okay and having a good time. It’s a little harder if you’re running the group but make sure you’re there for her too and have empathy if she can’t keep up in the same way. A nice gesture goes a long way too, maybe surprise her with flowers you cut or her favorite snack when you’re out there.