From what I know, fort data-acquisition of temperature/fan-speed/voltage values not a smis-provider, but a package called "lm_sensors" is used on ESXi. I have spent many hours trying to get this software work properly on my linux-server and the best I can say about it is: it is "rather tricky" piece of software. But first you have to check what sensor-chips are on your motherboard, and if they are supported by lm_sensors (I think VMware dropped support of some/many consumer-grade chips from lm_sensors). Try to run "sensors-detect" (I do not remember if it is included in ESXi; if not, boot some live-cd) to find if it can see some sensors on your motherboard at all. This might be easily the biggest obstacle. If not, you'd have to re-compile lm_sensors and update the version on ESXi, which might not be trivial task...
And even if your chip is supported, data you get still might not be correct (i.e. you can get negative value for fan-speed or some crazy temperature-readings with mixed F/C degrees) and this would trigger errors/warnings in health status page. The thing to do is proper lm_sensors configuration, where necessary re-calculation coefficients and/or offset-values have to be defined. This is more like trial-and-error work and might take some time. If for example you see "-11.8V" for "12V" reading, the question is: do you get proper value by applying the multiplier (-1), or by adding constant +24? Etc, etc. Really not easy, and I think VMware did this only for server-grade motherboards you can find on HCL (and not even all of them)...