Not so fast, young Bob,

Those temperature sensors weren't measuring the temperature of the *ground* that the wheel was on, they were measuring the temperature of the *wheel* that was on the ground.

The difference may seem trivial but is all-important. The wheel is part of a metal structure with internal sources of heat and very different reflectivity and thermal properties than the soil. Heat conducts down the rover suspension into the wheels, and out of the rover wheel motors into the wheels. Sunlight is very good at heating metal surfaces exposed to its rays try sitting on a metal park bench on a sunny day, and you'll know what I mean!

Don't take simplistic data to support a complex situation.

What would be more significant would be a series of depth reading of temperature on an inserted thermocouple probe placed just below the surface. That would show the skin depth of penetration of solar warmth into the soil.

We should also see properly calibrated mini-TES images that show individual rocks getting warm in the sun. Listen carefully to what is said about thermal conditions in light of these readings - it's a subtle thing to understand, so keep your mind open...

And don't forget that as soon as you have any H2O present, it's huge thermal capacity (both specific and latent) and its enhanced conductivity make it a great way to average out diurnal temperatures and PREVENT melting in the brief afternoon warmth.