I have asmall apt complex where I pay the heat. I have a honeywell t87f thermostat and a honeywell tg510a 1001 thermostat guard.they break in the guard and turn heat up. Is there a thermostat or guard they make that will stop them.

This is probably the best manufacturer of guards available:

STI Thermostat Covers (http://www.sti-usa.com/category.asp?Class=cab_cov_enc&Sub=therm)

But any guard may be tampered with or removed.

Best to change the stats also to one that has a max temp of 72 degrees:

Programmable Thermostat, Green Thermostat, Tamper Proof Thermostats, Tamper Thermostats, Locking Thermostat, Thermostat Security, Tenant Heat (http://www.landlordstat.com/)

I can`t imagine why anyone would want to rent an apartment that they couldn`t have control of there own comfort living area,

Try being a landlord with 200 units, landlord pays for heating fuel, and tenants have the heat up to 80, even when not needed, and windows open.

72 degrees is sufficient for most tenants when heat is included in the rent.

Don't usually see tenants that pay their own heat with thermostats up to 80 and windows open,

A honeywell 9000 is a touchscreen thermostat and is pretty pricy but it has a lockout feature in its programming. Most honeywell digital thermostats will have a max heat set point (usually 90 degrees) that could be set to 70 for example.